In ancient times, Leros, with Kalymnos, named Kalydniai Islands or Kalyndia. The name Leros, allegedly derived from "lefros», which means smooth, smooth as Leros, unlike the rocky Kalymnos is almost flat. 
Leros was inhabited since the 3rd millennium BC. The first inhabitants were Carians, Leleges, Phoenicians and Cretans (Minoans). Leros like all the Dodecanese, participated in the Trojan War.
The "Battle of Leros», It took place in World War II when "Battle Dodecanese». started on 26 September 1943, with the bombing of the island, the German air force and culminated in 12 November 1943, the German forces land landing. After battles 4 days, at 16 November 1943, Leros was occupied and the "Battle of Leros" ended with the victory of the Axis powers, which was the last.
Leros was a place "exile" Political prisoners, the time of the April dictatorship (1967-1974), in place Partheni. Leros was also a therapy place patients or psychopaths "Colony psychopath Leros», writes relevant marble inscription (1957).
Leros is an island of south Aegean sea, and is one of the Dodecanese islands. It is between the island of Patmos, Lipsi and Kalimnos (1 nautical mile) and is 179 nautical miles from Piraeus and 7 nautical miles from the Turkish coast.
It has a population of 7.917 inhabitants, It is 54,052 kmand has a coastline of 82 km, which shows the rich variety of its coasts, which form deep gulfs.
The island's capital is Agia Marina where along with Platanos and Panteli are, a large settlement, designated as a traditional. 
Leros is a landscape with constant changes. Outline with intense marine division that forms deep shelters and large bays in many places. Most of the island is lowland, with plains reaching the sea, with low mountains.
The soil of Leros has a mild relief with the highest peak Skoubardos, (327 m.) in the south, while, along its entire length, the hills of Kastelli, Tourloti, Katevati, Klidi, Patelos, Tourtousas and Vathia Lagada develop from north to south. Among them, low plains and fertile valleys are formed, where, due to the mild climate, the cultivation of fruit and vegetables, citrus and olives is favored.
The climate of Leros is Mediterranean, with mild winters, several rains, strong winds at times and periods with relatively high sunshine. The dry-warm period lasts from late April to mid-September.
The warmest month in the region is August (27,1oC) while the coldest is January (11,9oC). The average annual temperature range is 15,2oC.
The humidity rate ranges from 57.6% in July to 72.4% in December.
A large percentage of the island's residents are employed in the State Psychiatric Hospital, making it the largest employer on the island.
The rest deals with tourism, beekeeping and fishing.