The details of the history of Idukki are not much known and there are no proofs of Paleolithic age. The region of Idukki was earlier ruled by the Chera dynasty and the Kongu Nadu. The capital of the Chera Dynasty, Kuzhumoor was at Kumily in present day Peerumade taluk. During the period from 800 AD to 1102, the areas included in the present day Devikulam, Udumbanchola and Peerumade taluks were under the control of the Vembolinad kingdom. For some time, this was under the control of the Thekkumkoor Rajas. Idukki came under the rule of the Poonjar Raja in the 16th century. Manavikrama Kulasekhara Perumal established the Poonjar Kingdom and bought the High Range areas from the Thekkumkoor Raja. So a large part of Idukki came into the hands of Poonjar Raja.
When the British invaded Kerala, the European planters came to Idukki region. In 1877, the Poonjar ruler, Kerala Varma leased around 227 sq kms of land to the British planter, John Danial Manroe. This area was largely covered by thick forests. North Travancore Land planting and Agriculture society was formed by him and there were members in this society. These members then developed estates of their own in the High range areas. Many planters migrated to the high range areas that were covered by forests. Several plantation industries were started and deforestation started, leading to the destruction of vast area of evergreen forests. The high ranges here were attracted by the Scottish planters and they built many bungalows in Munnar which are very attractive. Idukki was formed as a separate district in the year 1972.