Looking around the internet for a brief history of Leros, we came across the following text which was repeated in a number of web sites.  We can't vouch for its accuracy, and we hope that we will be able to provide our own soon. 

The island of Leros has a rich historical past which has developed due to its strategic position in the S.E. Aegean. Evidence of its early importance dates as far back as the Neolithic period and artifacts have been discovered at Partheni which date from about 8000 to 3000 BC.

The first inhabitants of Leros were the Carians, the Leleges, the Phoenicians and the Cretans (led by Radamanthys, the brother of King Minos). The island was then conquered at a later date by the Dorians. The great poet, Homer, writes of Leros and its neighbouring island, Kalymnos as being involved in the Trojan wars and, according to the historian, Herodotus, Leros developed close commercial, political and intellectual links with the Ionians of Miletos. During the 5th century Leros blossomed intellectually as a result of influences from such cultural ancient heroes as the satirical poet, Dimodikos and the historian, Pherekydes.

The island became part of the Athens Alliance following the Persian Wars and there is evidence that it was visited by great and wealthy persons. Such proof of this has been found in the excavation of coins and funerary steles from the period. This is not surprising as it was an important location for shipping and the moral philosopher, Plutarch, refers to the capture of Julius Caeser's island of Farmako which lies next to Leros.

During the Byzantine period, Constantine the Great incorporated Leros into the theme of Samos and many magnificent Christian churches were built as well as the castle and the Panayia (Blessed Virgin) church on the hills overlooking what is now Platanos. A further castle of Lepides, known today as Paliokastro, was also built and its ruined walls can still be seen, as well as many other outstanding Byzantine monuments such as the early Christian church at Partheni, the church of Ayia Varvara (St. Barbara) which was built from the marbled ruins of ancient Lerian monuments.

Occupation by foreign powers has chequered the history of this small but strategically important Aegean island. In 1314, Leros was occupied by the tyrannical Knights of St. John of Rhodes who governed it despotically until the Turks invaded and took command of the entire Aegean archipelago, plundering the islands in their wake. To the credit of the Lerians during the Turkish occupation, they managed to hold on to an element of autonomy and later, when the Greek Revolution broke out, some of the people of Leros were the first to resist their oppressors.

After the independence of Greece in 1829 all the Dodecanese islands were ceded to Turkey by the London Protocol in exchange for Euboea. From 1912 to 1943, the island was occupied by the Italians and during this time, the intention was to develop Leros into an Italian naval base. Over several decades important defence work was carried out and military installations built with a new deep sea port created at Laki. Many buildings were demolished and in their place grand buildings were erected in the then, new, modern style that is now associated with Fascist architecture of the 1930s.

During the Second World War, the Greek Sacred Battalion, together with the British alliance liberated the island following the Italian capitulation. However, after almost 50 days of bombardment from German air raids, the Germans went on to occupy the island until the end of the war in 1945.  There are some books and articles on the subject, one of which is Churchill's Folly- Leros and the Aegean  published by Cassell Military Trade Books

The withdrawal of the Germans was followed by a two year occupation by English armed forces, which culminated in March 1948, with Leros and the whole of the Dodecanese finally being united with Greece.