The Capture of Lemnos took place in October 1912 during the First Balkan War, serving as the opening action between Greek and Ottoman forces in the Aegean Sea. The strategic value of the island of Lemnos had been recognized by Greek naval planners for many years, as it lay at the entrance of the Dardanelles Strait and offered an excellent natural harbour in Mudros Bay. The island was occupied with little resistance from the small Ottoman garrison, which was taken prisoner. Mudros Bay was made into a forward naval base for the Greek navy, enabling it to blockade the Dardanelles and secure naval dominance in the Aegean. This obstructed the movement of Ottoman reinforcements to the front lines, and allowed the capture of the remaining Ottoman-held Aegean islands over the following months. Ceded to Greece in 1914, due to the subsequent outbreak of World War I, the island's status remained disputed, and its annexation to Greece was not confirmed until the Treaty of Lausanne in 1923.
Background
The island of Lemnos had been ruled by the Ottoman Empire since 1456, when Sultan Mehmed II captured the domains of the Genoese Gattilusio dynasty in the northeastern Aegean Sea. The population of the island remained predominantly Greek throughout Ottoman rule. French scholar Vital Cuinet, in his 1896 work La Turquie d'Asie, recorded a population of 27,079, of which 2,450 were Muslims and the rest Greek Orthodox.
Already during the Greco-Turkish War of 1897, the Greek government had considered the occupation of the northern Aegean Islands, chiefly Lemnos and Imbros, due to their strategic location at the entrance of the Dardanelles Strait. However, despite the superiority of the recently modernized Royal Hellenic Navy over the Ottoman Navy at that time, the Greek naval command hesitated to carry out these tasks, and the rapid defeat of the Greek army on land in Thessaly led to the quick conclusion of the war in a humiliating Greek defeat. In subsequent years, Greek naval strategists such as Konstantinos Dosios (', 'Greece and Sea-Power', 1900) and Periklis Argyropoulos (', 'The Naval Programme of Greece', 1905) pointed out that the task of seizing Lemnos would be of crucial importance in a Greco-Turkish naval war. The importance of Lemnos was also appreciated by Italy, which envisaged occupying it during its own 1911–1912 war with the Ottomans, only to back down due to the vehement opposition of Austria-Hungary.
Nevertheless, when the First Balkan War broke out in October 1912, existing Greek plans called for the port of Oreos in northern Euboea to be the wartime anchorage for the Greek fleet, as in 1897. This was a choice that was fraught with distinct disadvantages for the Greeks: unlike in 1897, the Ottomans' main warships were more modern, faster and powerful than the Greeks'. In addition, according to the 1912 Greco-Bulgarian military convention that signalled Greece's entry into the Balkan League against the Ottoman Empire, the Greek fleet undertook the role of establishing dominance in the Aegean Sea and interrupting seaborne Ottoman communications between Asia Minor and the Balkans. This meant keeping a close watch on the Dardanelles to prevent a sortie of the Ottoman fleet. In that case, a forward anchorage was an absolute necessity, both to allow the Greek patrol ships to recover in the harsh winter conditions of the Aegean, as well as to allow them to be supported in a timely manner by the slower Greek battleship squadron. Mudros Bay in Lemnos satisfied this need.
Capture of Lemnos
At the outbreak of the war, the commander-in-chief of the Greek navy, Rear Admiral Pavlos Kountouriotis, divided the fleet into two: the bulk of the available ships became the Aegean Sea Fleet, under his own command, and the remainder formed a small Ionian Sea Squadron. It was also apparently Koundouriotis, on his own initiative, who selected Lemnos as the forward base for the Greek fleet, instead of Oreos. The Greek Prime Minister, Eleftherios Venizelos, was persuaded by the admiral's suggestion, but insisted on obtaining the consent of the British government for this first.
thumb|280px|View of the harbour and citadel of Myrina in 2013
The Aegean Fleet under Koundouriotis set sail on , followed by the passenger steamer Pineios, carrying two companies of the 20th Infantry Regiment to be used as a landing force. The fleet arrived at the capital of Lemnos, Kastro (Myrina) at 14:00 on the next day, and Koundouriotis issued a demand for the surrender of the island's garrison. The Ottoman forces on the island were small, some thirty men and three officers according to Turkish sources, while Greek sources give 47 men and three officers. The local Ottoman governor, stalling for time, replied that he was unaware of the declaration of war,