The island of Serifos
Serifos (Greek: Σέριφος, Latin: Seriphus, also Seriphos) is a Greek island municipality in the Aegean Sea, located in the western Cyclades, south of Kythnos and northwest of Sifnos. It is part of the Milos regional unit. The area is 75.207 square kilometres (29.038 sq miles). It is located about 170 kilometres (92 nautical miles) east-south-east of the Athenian port of Piraeus. The Cyclades are one of the island groups which constitute the Aegean archipelago. Their name in Greek is Κυκλάδες and this refers to the fact that they are around (i.e. “you circle”, κυκλάς) the sacred island of Delos. The largest island of the Cyclades is Naxos, however the most populated is Syros.

The earliest references to Serifos show the name as it is today, but its meaning has been lost to time. However, there is no doubt about the importance of the island during prehistoric times, presumably because of its mining wealth. One etymology theory states that the name derives from the Phoenician root “s-r-p”, meaning ore treatment. According to the classical writers, the first inhabitants of Serifos were Aeolians from Thessaly in northeastern Greece. Other sources indicate that settlers from Caria (Asia Minor) and Phoenicia were ousted by Minoan Cretans. Only a few traces of settlements have been found so far, dating from the Protocycladic (3rd millennium BCE) and the Mycenaean (1400-1200 BCE) eras. Some remnants of ore smelting at Bronze Age sites have been found on Serifos, as well as on Crete where ships transported the ore.

In the late 19th century Serifos experienced a modest economic boom from the exploitation of the island's extensive iron ore deposits. The last of the mines closed in the 1960s, and Serifos now depends on tourism and small-scale agriculture.




The history of mining on Serifos
Serifos is rich in minerals, and mines are a significant part of the history of the island. There are still places on the southwest side where visitors can visit some of the most recent (19th century and early 20th century) sites and view what remains of the buildings and machinery. Whilst iron and copper mines were also worked in antiquity, as evident from a few existing traces of sites, there are no writings about these mines so not much is known about them.

However, during ancient times Serifos was known for its ore deposits and these seemingly gave the island such wealth and strength that, in the 6th century BCE, it obtained its own currency.

After Persian ruler Xerses I, also known as Xerxes the Great, organised a massive invasion aiming to conquer Greece in the 5th century BCE, Serifos islanders refused to submit to him. Although the mines being worked at the time would probably have bestowed a fair degree of prosperity on the island, information about them is lacking and it seems that Serifos was actually treated with some contempt on account of its alleged poverty and insignificance, although the behaviour of the Persians was likely because of the belligerence shown to them by the inhabitants of Serifos.

Eventually, the Spartans established an oligarchic regime on Serifos, which lasted until 377 BCE, after which the island saw a number of different rulers until the Roman invasion of Greece in 146 BCE. During their period of conquest, Serifos was used by Roman emperors as a place to exile political opponents. There is some evidence of Roman mining on the island though, with finds in several areas which prove that both the extraction and processing of minerals took place.

After Roman times until the 13th century, Serifos was part of the Byzantine Empire (a continuation of the Roman Empire, but during this period there are just a handful of references about the island. Serifos rises up from obscurity after the the Doge of Venice, Dalmatia and Croatia gave his subjects the authority to conquer the Aegean and, with the sack of Constantinople which occurred in April 1204 marking the culmination of the Fourth Crusade, the Francocracy reopened the mines on Serifos after supposedly almost 1,000 years of inactivity. The Venetians who arrived systematically organised all the mining operations on the island, including relocating slaves from other areas to maximise the production in order to cover their great naval fleet needs. Serifos remained a minor dependency of the Venetian dukes on the archipelago for around three hundred years. There was a brief re-occupation by the Byzantines, but Venetian dominion was consolidated in 1296. After which, for the next hundred and fifty years there were several benefices on the island, separated based on mineralised zones. In 1394, the first recorded miners strike on Serifos took place, against the Venetian eupatrid (a hereditary noble or landowner), Nikolaos Adoldos. A tyrannical ruler, he was later condemned in Venice never to revisit the island again. His share was confiscated and given in 1433 to Alvise Michieli, first lord of the whole Serifos. His descendants remained in power until 1536.

Two years later, a raid by the infamous Barbary pirate Hayreddin Barbarossa resulted in the almost total desertion of Serifos and also marked the beginning of Ottoman rule. Barbarossa was notorious for his successes against Christian vessels in the eastern Mediterranean. Although never actually occupied, the island suffered at the mercy of pirates, or in the vortex of the Venetian-Ottoman wars. For many years Serifos remained a closed agricultural society with few inhabitants. Those who stayed struggled for survival with meagre means under an unbearable taxation system. All mining activities stopped.

The situation on Serifos changed to some degree after a short Russian occupation (between 1770 and 1774). Its economy showed a relative bloom, thanks to the island’s commercial ties with the richer island of Hydra and the contribution of well-off immigrants who had settled in Constantinople (renamed Istanbul in 1930) and present day Romania.

Just under a century later, after a royal decree by King Otto in 1861, the mines on Serifos began to fully operate again, at both Koutalas and Megalo Livadi. Otto Friedrich Ludwig von Bayern was a Bavarian prince who ruled as King of Greece after the establishment of the monarchy on 27th May 1832. Under the management of the Hellenic Mining Company, which belonged to the Greek National Bank, the mines operated more intensively from 1869. Besides the Serifos mines, HMC also operated in the mines of other Greek areas. Their ambitious plans for industrial production in the mining area of Kimi on Serifos, using lignite from there for the reduction of iron ore, failed. This was mainly due to the huge technical problems that were encountered, but also in part because of the lack of domestic market demand. Thus, in 1875 the Hellenic Mining Company filed for bankruptcy.

In the 1880s, a new company appeared on Serifos with French interests, La Société des Mines de Spiliazeza au Lavrium et de Seriphos (known on the island as Serifos-Spiliazeza). It was funded by the Imperial Ottoman Bank (a French–British venture) and other wealthy people from Constantinople, such as Andreas Syggros and Giovanni Baptista Serpieri. These men had also invested a fortune to gain the concessions to re-open the Lavrion Mines on the mainland of Greece, near Athens - the same mines that had once made ancient Athens an economic powerhouse from the silver, copper, and lead that they produced.

In 1884, Serifos-Spiliazeza commissioned by contract the operation of the mining on Serifos to German mining engineer Emil Grohmann (10th June 1848 - 11th February 1904). The company was initially based in Koutalas and a small community soon built up around it, but during Grohmann’s years they were transferred to Megalo Livadi, which was the main harbour on Serifos for exporting ore, and equipped with all the necessary sorting and shipment facilities. In fact, there was also a conveyor system with rails and wagons that assisted the operations, part of which can still be seen today, along with loading bridges at the moorings. The company built its headquarters in Megalo Livadi, a two-story neoclassical building, the ruins of which still stand at the end of the beach. Located on the southwestern part of Serifos Island, the settlement of Megalo Livadi gradually grew in size because of the numerous mines located nearby. During its peak the general area flourished.


Exploitation of the mineral resources by Emil Grohmann began in 1885. With a small yet highly influential section of the community and also the police on his side he virtually compelled many inhabitants of the island to work in the mines, asking them to forfeit their land or forcing them to give it over to him against a miserable wage. Grohmann always performed his duties with a view to maximising his own benefit and profit. It was around this time that the island's population increased by approximately 2,000 people, since workers came to work in the mines from other islands in the Aegean (Amorgos, Karpathos, Paros, etc.), as well as from other regions of Greece (e.g. the Peloponnese). In order to accommodate the growing population, Grohmann built up the infrastructure to support his mining operations. Megalo Livadi is a picturesque coastal village, but further inland and up in the hills is Megalo Chorio (Greek: Μεγάλο Χωριό), or Mia Chorio, also Mega Horio. This was the ancient capital of Serifos. Today, Megalo Chorio is an almost uninhabited village. Megalo means “large” in Greek and chorio means “village”. Thus, Megalo Chorio was the “Big Village” and it was indeed the largest settlement of the miners era too. Between 1880 and 1920, the villages of both Megalo Livadi and Megalo Chorio were at their zenith with many residences built up around them. There was also a school (“Grohmann School”), plus numerous businesses and services including grocery stores, bakers, shoemakers, tailors, baths, and police station. There were two medical facilities. What remains of one of the hospitals has survived to this day, but the other one has disappeared, dragged down by the collapse of a mine gallery. Shortly after the closure of the mines, Megalo Chorio was gradually abandoned. Today it is almost deserted and what you will find there now is mainly ruins, as well as the entrances to some old mine galleries.

Wood-carvings made for some of the churches on Serifos, as well as the transport and storage of several ancient relics from Cyclops Cave, demonstrated that Grohmann was, partially at least, interested in the heritage and welfare of the island too. In one version of Greek mythology, the Cyclopes (giant one-eyed creatures) are supposed to have resided on Serifos, which is why it is often referred to as the “island of the Cyclopes”. According to myth these creatures were the children of Poseidon and they once lived in the southwest part of the island between Megalo Livadi and Koutalas where Cyclops Cave is located.



After the death of Emil in 1906, the company management was taken over by his son Georg Grohmann (24th December 1875 - 21st December 1945), but the exploitation of human labour continued even after Emil Grohmann’s succession by his son Georg. He was educated at the respected Clausthal Mining Institute in Lower Saxony, Germany but, despite his young age, he proved to be more brutal than his father.


Working conditions in the mines were incredibly harsh and, according to historians, many hundreds of workers lost their lives in the galleries due to inhumane working conditions and the overall lack of safety measures. Workers were forced to be at the mine by dawn and had to stay until sunset. For those who did not live on the southwest of the island - lots of people were located in remote areas elsewhere - the journey to and from the mines was often one of many miles along extremely rugged paths. Some of these old paths still exist, such as the one leading from Giftika (in the central part of the island) to the settlement of Ano Chora (above the village of Livadi on the southeastern side), so it is possible to walk part of an old miners route and get an idea of the journey they had to take twice a day.



It has been said that the employees of both the school and the hospital were paid by the workers themselves, and not by the mining company. Furthermore, the miners gave back 2% of their wage to Grohmann, for unknown reasons, whilst 1 drachma each month was withheld, for the erection of a church that was never actually built. If anyone was late for work they were not allowed to continue working that day, meaning they did not get paid. Everyone was forced to follow the commands of Georg Grohmann and the punishment for disobedience was severe, and often violent.

The remaining mining companies on Serifos were slowly acquired by Serifos-Spiliazeza and workers from the Greek islands of Amorgos, Karpathos, Mykonos, Paros, and the Greek region and islands of Euboea came to Serifos to become mine workers. The population reached 4,400 in 1912, of which nearly half worked in the mines. As more and more “foreign” workers arrived on the island, people got to know about the awful conditions in the mines, and they looked into the existing laws concerning both working conditions and working hours. Since 1901 there had been a “Miners Fund”, the “Regulation of Mining Operations” had existed since 1910, and the “Casualties Care Decree for Miners” had been around since 1912.

The first severe mining crisis during Grohmann management occurred in the 1910s as a result of international competition with countries who had plenty of οre, also richer in concentration and cheaper. Many mines shut down on other Greek islands and production by Serifos-Spiliazeza steadily declined, reducing from 172,000 tons in 1910 to 110,000 in 1914, and then just 27,700 tons in 1915. After the First World War started it bought many problems, but at the same time there were ideological and political rumblings within the general workforce and the workers parties. These resulted in strikes at many of the Greek mines that were still operating.

In August 1916, as the First World War raged, Greece was suffering from huge division with a continuing struggle between pro-German Greek King Konstantínos I (Constantine I) and Eleftherios Venizelos from Crete, a prominent leader of the Greek national liberation movement who supported the Allied (or Entente) Powers of France, Russia and the United Kingdom. During part of World War 1, Greece had two governments, a royalist pro-German one in the capital Athens and a “Venizelist” one in northern Greece (Thessaloniki), which supported the Entente. The two governments were only united when Greece officially entered the war on the side of the Allies in 1917.

During this period of unrest, Konstantinos Speras arrived on Serifos. He had been born on the island in 1893, but went to Egypt at the age of 14 where he studied in a French school. He then worked as a tobacco worker in Cairo and Alexandria, where he was introduced to the union movement. In March 1914 he worked in Greek tobacco plantations in Kavala in northern Greece, but after getting involved in a big strike there, he was imprisoned and later transferred to Tripoli, Libya. He decided to use his knowledge and experience to organise and establish a “Miners Association” on Serifos. This was founded on 24th July 1916 with 460 members initially. As the head of this association, he contacted the Greek Government and in his dispatch he described the unacceptable working conditions. He also communicated with Grohmann at Serifos-Spiliazeza and requested that the company comply with the demands of the mine workers who sought the introduction of an 8-hour work day, a wage rise, plus the establishment of safety measures inside and out of the mines. Neither the Government, nor Georg Grohmann responded. The following is an excerpt from the letter of the union to the Ministry of Economy in Athens:

 


The 1916 miners strike on Serifos and the events that followed
As a result, a general strike began on 7th August 1916 when the miners refused to load the ship “Manousi” from Andros Island which had orders to load and leave immediately for northern Europe. Regular employees of Serifos-Spiliazeza were unable to control the situation, so Grohmann requested help from the authorities. The government in Athens duly dispatched a 30-man contingent of the Hellenic Gendarmerie from nearby Kea Island to quell the workers revolt and they arrived on 21st August. A group of around 400 miners had gathered by a loading bridge at the docks in Megalo Livadi as well as about 1,500 women and children.




The commanding officer of the gendarmerie detachment, Charilaos Chrysanthou, took Speras and his strike committee away, supposedly to seek a negotiated end to the problem. However, once he had detained them Chrysanthou then bizarrely lined his men up opposite the group of men, women and children on the dock and, with the guns of his men pointed at the group, he demanded that they end the strike. He gave the strikers five minutes to disperse, but before the deadline was up he shot and killed with his pistol Themistoklis Kouzoupis, a 24-year-old miner who had actually married just three months earlier. He then ordered his men to fire at the strikers. Three other miners were shot and killed; Michalis Zoilis, Michalis Mitrophanis, and Yiannis Protopapas. As a result, the group of miners along with the women and children rushed the gendarmes who were being assisted by police. Chrysanthou was hit with a rock thrown by one of the women in the crowd and he died. The local police chief, Ioannis Triantafillou, was also killed by the strikers and according to sources his body was thrown into the sea.

In the confusion immediately following the shootings and melee, the strikers assumed that Speras and the arrested union management were dead. Speras by all accounts was unaware of what had happened at the loading dock. The indignant strikers took dynamite, plus the weapons they had seized from the gendarmes, with the aim of blowing up Serifos-Spiliazeza company headquarters. The company employees in the offices took out their weapons and shot at several strikers who were heading towards them. In the meantime, an injured gendarme went to the police station where Speras and the others were being detained and informed the police there about the events and that Chrysanthou and the police chief were dead, also that the strikers were on their way to blow them up. He proposed the release of the trade unionists and this was duly done. Speras, who was thought to be dead, managed to eventually calm the mob down.


Speras with his strike committee and the miners then took control of the island’s telegraph office, police station, magistrates court, and other public institutions. They sent a message to the French Navy who were anchored nearby at the island of Milos and asked that Serifos be put under their protection since they no longer trusted the government of Athens. According to some accounts a French flag was also raised on the island! The French declined to intervene as they did not want to get involved in Greek affairs or cause a diplomatic incident. However, a French Navy vessel, “Henri IV”, did subsequently arrive and its captain declared his support for the request of protection and agreed to keep the peace on Serifos. A Greek vessel, “Avlis”, eventually arrived around fifteen days later from the island of Syros with 250 soldiers and a magistrate on board. In early September 1916, the Greek authorities took back control of Serifos. Speras and a few of the strikers were arrested and sent to be detained on Syros Island. In 1917, Speras was transferred to a jail on Crete. However, he was later released without charge when the royalist government of Greece was ousted in June that year. Grohmann was put back in charge of the mines again, but he also agreed to concede to some of the miners requests by granting improved working conditions and adopting an 8-hour workday.

In addition to those people mentioned above who tragically lost their lives on 21st August 1916, two more people were also killed, one died on the way to hospital and the other after a few days. Despite this, no one was subsequently prosecuted for the awful events that occurred that day, nor for taking the strike action that led up to them. Eight people in total died and dozens were injured.

In October 1918, Speras took part in the establishment of Genikí Synomospondía Ergasías Elládos (GSEE) - the General Greek Confederation of Labour, but there were significant differences of opinion between the working class movement (who were concerned with workers rights) and the authoritarian socialists (who sought political power). In November 1918, Sosialistiko Ergatiko Komma Elladas (SEKE) - the Socialist Labour Party of Greece was formed and Speras became a member. In March 1920, he participated as special secretary in a conference of miners and coal miners held in Athens which aimed to establish a miners federation. Due to his supposed “anti-party elements”, in April 2020 Speras was expelled from SEKE. He was ultimately expelled from the GSEE too and this was orchestrated by the communist party, formerly SEKE and now called Kommounistiko Komma Elladas (KKE) - the Communist Party of Greece. Speras denounced them for unleashing a war against him. Not much is known about his life from then on. From 1930 onwards he worked as a ticket booking clerk for one of the Athens railway companies and continued his workers rights activities. During the German occupation of Greece he was living with his family in Athens. On 14th September 1943, his life ended suddenly when he was lured to a remote location outside Athens by communist-led partisans and assassinated. During his fifty-year lifetime Speras had been either arrested, jailed or sent in exile over a hundred times and he is regarded now as one of the pioneers of the working class trade-union movement in Greece.

The local community have raised a monument for the workers that died and for those that stood with them during the strike on Serifos. There is an annual small ceremony to commemorate the fallen. A bust of Speras has been raised too. It is located a few metres from the beach in Megalo Livadi, in front of the old police station building where he was detained in the 1916 strike.







Consequence of the 1916 strike
It has been suggested that the strike action which took place in August 1916 was instigated in some way by the Allies Powers fighting during World War 1 in order to hit the supply lines of the German army. It is difficult to say whether this was actually the case because we only have the facts as they were reported at the time, along with a few oral accounts from those who were there. Whilst there were features of a rebellion on the island during the month of strike action on Serifos, the true facts have been muddied by conflicting information and press reports.

However, what is known is that the major uprising at the Serifos mines, in addition to smaller events on Serifos during the 1910s, and in the mines of Lavrion, Naxos and Kimi, as well as in other industrial sectors, led to the gradual decrease of the working hours in the mines. In 1925, the Greek state officially established the first 8-hour workday in the mines, applying a law that had been voted in since 1920, but one which was never fully enacted. From 1925, operations in the mines of Serifos took place in two 8-hour shifts, from 06.00 to 14.00 hours and from 14.00 to 22.00 hours. The very same law was eventually expanded to other business sectors in 1932 and then in 1936, when Ioannis Metaxas was Prime Minister of Greece, to those remaining professions.

Closure of the mines on Serifos
During the 1920s the mining sector was in recession, until the crash of 1929 when many mines were forced to close. A partial recovery began in 1934 when, under the direction of Georg Grohmann’s son Emil (who was named after his grandfather), the mines of Serifos exported about 500,000 tons of ore, mostly to Germany (due to a specific agreement), but also to the United Kingdom, the Netherlands, Poland, and France.

At the time of German occupation in the Second World War, although the Cyclades were under Italian military control, the mines themselves were being exploited by German forces, with Grohmann - now an officer in the German army - being the “technical supervisor”. When World War 2 ended, the Grohmanns were regarded as collaborators and left Greece. Their business interests then led them to South Africa. Six years later, in 1951, Serifos-Spiliazeza mining company ceased operations. Although a few small mining operations did continue on the island, carried out by small Greek businesses and joint ventures, they too were soon forced to stop due to high costs and the plummeting price of ore price throughout the world. By 1965 all of the mines on Serifos had completely ceased to operate and the result of that was a significant reduction in the population of the island.

The Greek Ministry of Culture declared all of the following structures to be historical monuments: the headquarters of the mines, the mine workers residences, and the loading bridges in Megalo Livadi and Koutalas. Also, any kind of remaining equipment was to be surrendered to nature and the wear of time. Serifos is in itself an Open Air Museum of mining activity.





The geology of Serifos
In the northern section of the island, calcareous slate with embedded marble is predominant, while in the southern section granodiorite or granite and partly gneiss form the main portion. Between the northern and southern rock formations, there are skarn deposits alternating with hornfels. Serifos Island is well known for large crystals of prase, ilvaite, and others.

The island has a remarkable subsoil of iron deposits (haematite and magnetite), formed by contact transformation at the border of granite penetration. In the southwestern part of the island at Koundouros, copper deposits have also been found as well as the remnants of ancient copper ore mining at a site with the eloquent toponym “Skouriés” (which means rusts in Greek) and can be seen as a large heap of dark slag (with copper minerals), slag locality site, above the adjacent bay of Avissalos.

On the upper part of Serifos, in the area of Moutoula near the settlement of Galani, there was a small discovery of mixed sulphide minerals and in the past there was limited exploitation of this.

The iron and copper ore of Serifos cover an extensive area, laying on or near the surface. In the 19th century, the exploitation of iron and other deposits on Serifos entered a new period of glory, beginning in the late 1860s. Early on during this period mining activity focused on the surface iron deposits between Koutalas and Megalo Livadi, such as the open pit mine workings at Agia Triada). Galleries were limited and experimental in the main, with much of the material being extracted from large open mines. In addition to the mines themselves, an extensive network of railways was created, with machinery spaces, ramps, manoeuvres and loading bridges, interconnected with lanes and paths. The two main loading bridges were located in Megalo Livadi, another large one was established in Koutalas, plus one in each of the bays of Avissalos, Vagia and Tsilipaki.

References:

Fitros. M, Tombros. S, Williams-Jones. A, Tsikouras. B, Koutsopoulou. E, Hatzipanagiotou. K (Aug 2017) “Physicochemical controls on bismuth mineralization: An example from Moutoulas, Serifos Island, Cyclades, Greece”. American Mineralogist, vol. 102, pp. 1622–1631
https://www.researchgate.net/publication/318837682_Physicochemical_controls_on_bismuth_mineralization_An_example_from_Moutoulas_Serifos_Island_Cyclades_Greece

Pougkakioti. V (Apr 2018) “Structural Analysis and Restoration of the Old Loading Ladder in Mega Livadi, Serifos”. Conference Paper: 4th Biennial of Architectural and Urban Restoration, BRAU4
https://www.researchgate.net/publication/341313533_Structural_Analysis_and_Restoration_of_the_Old_Loading_Ladder_in_Mega_Livadi_Serifos

Papastefanaki. L (Nov 2019) “Family, Gender, and Labour in the Greek Mines, 1860-1940”. International Review of Social History, vol. 65, iss. 2, pp. 267-288
https://www.cambridge.org/core/journals/international-review-of-social-history/article/family-gender-and-labour-in-the-greek-mines-18601940/D4CB5B3084C1B681C017499A05ABE0D7

Korosidis. I, Voudouris. P, Kouzmanov, K (Mar 2022) “Distal Fe skarn deposits of Serifos Island: New mineralogical and geochemical constrains on the retrograde assemblage and associated ore mineralization”. 16th SGA Biennial Meeting, Conference Paper, pp. 180-183
https://www.researchgate.net/publication/358466709_Distal_Fe_skarn_deposits_of_Serifos_Island_New_mineralogical_and_geochemical_constrains_on_the_retrograde_assemblage_and_associated_ore_mineralization

Vlachopoulos. N, Voudouris, Panagiotis. V (Mar 2022) “Preservation of the Geoheritage and Mining Heritage of Serifos Island, Greece: Geotourism Perspectives in a Potential New Global Unesco Geopark”. Geosciences (Switzerland), vol. 12, iss. 3, pp. 1-27
https://www.mdpi.com/2076-3263/12/3/127

Journal of the Virtual Explorer: Serifos
https://virtualexplorer.com.au/article/2007/170/evolution-of-the-serifos-metamorphic-core-complex/structuralobservations.html

Serifos-Greece
https://www.serifos-greece.com/index.php/en/history-of-serifos

Cyclades Chamber of Commerce: Serifos
https://www.e-kyklades.gr/tourism/serifos_history?lang=en

Hellenica World: Serifos
https://www.hellenicaworld.com/Greece/Geo/en/Serifos.html

e-Serifos: “Explore the villages of Serifos - Megalo Chorio” (plus links to others)
http://serifos-en.e-serifos.com/explore-serifos/villages/megalo-chorio.php

e-Serifos: “The mines of Serifos”
http://serifos-en.e-serifos.com/what-to-do-in-serifos/mines-of-serifos.php

Discover-Serifos: “Ore mines”
https://www.discover-serifos.com/en/discover/serifos/mines

Mining Greece: “The 1916 Serifos incident”
https://www.miningreece.com/mining-greece/mining-history/the-1916-serifos-incident/

Kottis. L (July 2000) “Konstantinos Speras: The Life and activities of a Greek Anarchosyndicalist”
https://ngnm.vrahokipos.net/index.php?option=com_content&view=article&id=562:konstantinos-speras-the-life-and-activities-of-a-greek-anarchosyndicalist&catid=25&Itemid=178

Diary (Aug 2016): “Serifos Mining 1916 - A Class Clash” (in Greek)
https://www.imerodromos.gr/metallleia-serifou-1916-mia-taxiki-sygkrousi/

ERT News (21/08/2022): “Events of the Municipality of Serifos for the 1916 strike that led to the first implementation of the eight-hour shift in Greece” (in Greek)
https://www.ertnews.gr/anadromes/21i-aygoystoy-1916-h-aimatiri-apergia-sti-serifo-kai-i-proti-efarmogi-toy-ochtaoroy-stin-ellada/

Navypedia: Fighting Ships of the World - France
http://www.navypedia.org/ships/france/fr_bb_henry_iv.htm