ISTANBUL, April 25 (Reuters) - Kurdish militants who have fought a decades-old insurgency against Turkey will start their withdrawal from Turkish territory in two weeks, advancing peace a peace process meant to end a conflict which has killed more than 40,000.
Following are details on the Kurdistan Workers Party (PKK).
* PKK ORIGINS - Abdullah Ocalan founded the group in 1978. It took up arms against Turkey in 1984 with the initial aim of creating an independent Kurdistan in the mainly Kurdish areas of Turkey, Iraq, Syria and Iran. It is now seeking greater Kurdish rights and limited autonomy in southeast Turkey.
* LOGISTICS - The PKK is listed as a terrorist organisation by Ankara, the United States and the European Union and is estimated to have up to 8,000 people under arms, mostly based in the mountains of neighbouring northern Iraq. It draws support from Kurds in Turkey and some Kurdish communities across Europe.
* UPSURGE IN VIOLENCE - Last summer saw some of the heaviest fighting between the PKK and Turkish forces in more than a decade. Between June 2011, when Turkish Prime Minister Tayyip Erdogan was re-elected for a third term, and late last year more than 800 people were killed. It was the deadliest outbreak of fighting since Ocalan's capture in 1999, according to estimates by the International Crisis Group.
* OCALAN IN PRISON - Ocalan was captured and sentenced to death by a Turkish court in 1999, but the sentence was reduced to life imprisonment in October 2002 when Turkey abolished the death penalty. He is now imprisoned on Imrali island south of Istanbul.
* POLITICAL PROGRESS - Intelligence officers and Kurdish politicians have held new talks with Ocalan since late last year and have agreed the outline of a plan to end the nearly 30 year-old conflict, including the withdrawal set to begin in May.
Sources: Reuters/Jane's World Insurgency and Terrorism Guide (Reporting by Nick Tattersall and David Cutler, London Editorial Reference Unit; Editing by Toby Chopra)