There has been an ancient acropolis of Myrina since the 13th century BC. The medieval castle was first built by the Byzantines in the beginning of the 12th century. A lot of materials came from the acropolis which disappeared.
Following the dissolution and division of the Byzantine Empire after the Fourth Crusade, Lemnos was apportioned to the Latin Empire, and given, in 1207, as a fief to the Venetian Navigajoso family.
During the last centuries of Byzantium, Lemnos played an important role in the recurring civil wars of the 14th century. Following the Fall of Constantinople to the Ottomans in 1453, the island was added to the domain of the Gattilusi of Lesbos, but following the fall of the Despotate of the Morea, Sultan Mehmed II conquered the islands of the North Aegean too and gave Lemnos as a domain to the brother of Thomas, last legitimate Despot of Mystras (and his ally) Demetrios Palaiologos, in 1462.
The island then fell under Venetian control. In 1476, the Venetians and the island's Greek inhabitants successfully defended Kotsinos against a Turkish siege, but the island was ceded to the Ottomans by the 1479 Treaty of Constantinople which ended the First Ottoman-Venetian War.
During the Sixth Ottoman-Venetian War, after a major victory in Dardanelles over the Ottoman fleet, the Venetians captured the island again on 20 August 1656, but the Turks recovered it barely a year later, on 31 August 1657, after a siege of 36 days. In 1770, Kastro was besieged by Count Orlov during the Russo-Turkish War of 1768–1774, during the so-called Orlov events. The walls of the castle were severely damaged in that siege.
In 1780, Hasan Gatzi pasha repaired the castle and equipped it with 150 canons.
On 8 October 1912, during the First Balkan War, Lemnos became part of Greece. The Greek navy under Rear Admiral Pavlos Kountouriotis took it over without any casualties from the occupying Turkish Ottoman garrison, who were returned to Anatolia. Lemnos became a forward anchorage for the Greek fleet, which enabled it to keep watch on the Dardanelles and prevent a foray by the Ottoman Navy into the Aegean. It was a crucial factor in the victory in the Balkan Wars.
Lemnos was the main military base of the allied forces in the ill-starred Gallipoli campaign against the Turks in WW I.
References:The Beckov castle stands on a steep 50 m tall rock in the village Beckov. The dominance of the rock and impression of invincibility it gaves, challenged our ancestors to make use of these assets. The result is a remarkable harmony between the natural setting and architecture.
The castle first mentioned in 1200 was originally owned by the King and later, at the end of the 13th century it fell in hands of Matúš Èák. Its owners alternated - at the end of the 14th century the family of Stibor of Stiborice bought it.
The next owners, the Bánffys who adapted the Gothic castle to the Renaissance residence, improved its fortifications preventing the Turks from conquering it at the end of the 16th century. When Bánffys died out, the castle was owned by several noble families. It fell in decay after fire in 1729.
The history of the castle is the subject of different legends.