Dersim is the former Kurdish name for the mountainous, isolated, present-day Turkish province of Tunceli. It is located farther west and nearer to the center of Anatolia than most of the other ethnic Kurdish provinces of Turkey. The province has a strong Alevi and Zaza-speaking population of ethnic Kurds who in the past have not necessarily supported Sunni Kurdish revolts such as those of Sheikh Said in 1925.
Dersim became notorious in the history of the Republic of Turkey for the third and final major Kurdish uprising before World War II. Led by the septuagenarian Alevi cleric Sayyid Riza, the Dersim revolt lasted from 1936 to 1938 and was defeated only with the utmost scorched earth tactics. The name Dersim was then changed to Tunceli to help wipe out the memory.
However, the province again played an important role in the Kurdistan Workers Party (PKK) uprising during the 1980s and 1990s. "Dr. Baran" (Muslum Durgun) led the PKK forces in the province until his reported suicide in 1994. Some believe that Dr. Baran was executed on orders of the PKK leader Abdullah (Apo) Ocalan for "passivism" — that is, failing to launch attacks on Turkish targets. His eventual successor was Semdin Sakik (Parmaksiz Zeki), who also had a falling out with Ocalan in 1998.
Historical Dictionary of the Kurds. Michael M. Gunter.