From 1978 until 2025, the Republic of Turkey was in an armed conflict with the Kurdistan Workers' Party (PKK) (Kurdish: Partiya Karkerên Kurdistanê) as well as its allied insurgent groups, both Kurdish and non-Kurdish.Bloomberg Sex Scandal Shake-Up Reinvigorates Turkish Opposition Party , 23 May 2010 The initial core demand of the PKK was its separation from Turkey to create an independent Kurdistan. In 2010, the PKK abandoned separatism in favor of autonomy and/or greater political and cultural rights for Kurds inside the Republic of Turkey.

Although most of the conflict took place in Northern Kurdistan, which corresponded with southeastern Turkey, the Kurdish-Turkish conflict spread to many other regions. The PKK's presence in Iraqi Kurdistan resulted in the Turkish Armed Forces carrying out frequent ground incursions and air and artillery strikes in the region, and its influence in Syrian Kurdistan led to similar activity there. The conflict cost the economy of Turkey an estimated $300 to 450 billion, mostly in military costs. It also had negative effects on tourism in Turkey.PKK: Targets and activities , Ministry of Foreign Affairs (Turkey), Federation of American Scientists."Turkey: The PKK and a Kurdish settlement" , International Crisis Group, 11 September 2012

A revolutionary group, the PKK was founded in 1978 in the village of Fis, Lice by a group of Kurdish students led by Abdullah Öcalan. The initial reason given by the PKK for this was the oppression of Kurds in Turkey. At the time, the use of Kurdish language, dress, folklore, and names were banned in Kurdish-inhabited areas. In an attempt to deny their existence, the Turkish government categorized Kurds as "Mountain Turks" during the 1930s and 1940s.Bartkus, Viva Ona, The Dynamic of Secession, (Cambridge University Press, 1999), 90–91. The words "Kurds", "Kurdistan", or "Kurdish" were officially banned by the Turkish government. Following the military coup of 1980, the Kurdish language was officially prohibited in public and private life until 1991.Toumani, Meline. Minority Rules , The New York Times, 17 February 2008 Many who spoke, published, or sang in Kurdish were arrested and imprisoned.

The PKK was formed in an effort to establish linguistic, cultural, and political rights for Turkey's Kurdish minority. However, the full-scale insurgency did not begin until 15 August 1984, when the PKK announced a Kurdish uprising. Between 1984 and 2012, an estimated 40,000 had died, the majority of whom were Turkish Kurdish civilians. Both sides were accused of numerous human rights abuses. The European Court of Human Rights has condemned Turkey for thousands of human rights abuses. Many judgments are related to the systematic executions of Kurdish civilians, torture, forced displacements, destroyed villages, arbitrary arrests, and the forced disappearance or murder of Kurdish journalists, activists and politicians. Teachers who provided and students who demanded education in Kurdish language were prosecuted and sentenced for supporting terrorism of the PKK. Similarly, the PKK had faced international condemnation, mainly by Turkish allies, for using terrorist tactics, which include civilian massacres, summary executions, suicide bombers, and child soldiers, and involvement in drug trafficking.

In February 1999, PKK leader Abdullah Öcalan was arrested in Nairobi, Kenya by a group of special forces personnel and taken to Turkey, where he remains in prison on an island in the Sea of Marmara. The first insurgency lasted until March 1993, when the PKK declared a unilateral ceasefire. Fighting resumed the same year. In 2013, the Turkish government started talks with Öcalan. Following mainly secret negotiations, a largely successful ceasefire was put in place by both the Turkish state and the PKK. On 21 March 2013, Öcalan announced the "end of armed struggle" and a ceasefire with peace talks.

The rise of Islamic State on Turkey's southern border illuminated diverging interests and ignited new tensions. In response to Islamic State's 2015 Suruç bombing on Turkish soil, the Ceylanpınar incidents saw the killing of two Turkish police officers by suspected PKK militants and the return to open conflict. Subsequently, the conflict resulted in about 8,000 killed in Turkey alone, with about 20,000 more in Syria and Iraq due to Turkish military operations. Numerous human rights violations occurred, including torture and widespread destruction of property. Substantial parts of many Kurdish-majority cities including Diyarbakır, Şırnak, Mardin, Cizre, Nusaybin, and Yüksekova were destroyed in the clashes or external operations.

New peace process discussions began in 2024. In early 2025, Öcalan called PKK to disarm. On 12 May 2025, the PKK announced its full dissolution to favor political means. However, Turkey's military will continue operations against the Kurdistan Workers’ Party (PKK) in regions where it remains active, despite the group's announcement of its dissolution.

History

Beginnings In 1977, a small group under Öcalan's leadership released a declaration on Kurdish identity in Turkey. The group, which called itself the Revolutionaries of Kurdistan also included Ali Haydar Kaytan, Cemil Bayik, Haki Karer and Kemal Pir. The group decided in 1974 to start a campaign for Kurdish rights. Cemil Bayik was sent to Urfa, Kemal Pir to Mus, Haki Karer to Batman, and Ali Haydar Kaytan to Tunceli. They then started student organisations that contacted local workers and farmers to raise awareness about Kurdish rights.

In 1977, an assembly was held to evaluate these political activities. The assembly included 100 people from different backgrounds and several representatives of other leftist organisations. In spring 1977, Öcalan travelled to Mount Ararat, Erzurum, Tunceli, Elazig, Antep, and other cities to make the public aware of the group's activities. This was followed by a Turkish government crackdown against the organisation. On 18 May 1977, Haki Karer was assassinated in Antep. During this period, the group was also targeted by the Turkish ultranationalist organization, the Nationalist Movement Party's Grey Wolves. Some wealthy Kurdish landowners targeted the group as well, killing Halil Çavgun on 18 May 1978, which resulted in large protest meetings in Erzurum, Dersim, Elazig, and Antep.

The founding Congress of the PKK was held on 27 November 1978 in Fis, a village near the city of Lice. During this congress, the 25 people present decided to found the Kurdistan Workers' Party. The Turkish state, Turkish rightist groups, and some Kurdish landowners continued their attacks on the group. In response, the PKK organised and armed members to protect itself, thus becoming more involved in the fighting between leftist and rightist groups in Turkey (1978–1980). During this time, the right-wing Grey Wolves militia killed 109 and injured 176 Alevi Kurds in the town of Kahramanmaraş on 25 December 1978 in what would become known as the Maraş Massacre.A modern history of the Kurds, By David McDowall, page 415, at Google Books , accessed on 1 May 2011 In Summer 1979, Öcalan travelled to Syria and Lebanon where he made contacts with Syrian and Palestinian leaders. After the Turkish coup d'état on 12 September 1980 and a crackdown which was launched on all political organisations,Gil, Ata. "La Turquie à marche forcée," Le Monde diplomatique, February 1981. during which at least 191 people were killedToday's Zaman Fears of suicide prompt Evren family to remove coup leader's firearms , 19 January 2012 and half a million were imprisoned,The Economist Erdogan pulls it off , 13 September 2010 most of the PKK withdrew into Syria and Lebanon. Öcalan went to Syria in September 1980 with Kemal Pir, Mahsum Korkmaz, and Delil Dogan being sent to set up an organisation in Lebanon. Some PKK fighters took part in the 1982 Lebanon War on the Syrian side.

The Second PKK Party Congress was then held in Daraa, Syria, from 20 to 25 August 1982. Here it was decided that the organisation would return to Turkish Kurdistan to start an armed guerilla war there for the creation of an independent Kurdish state. Meanwhile, they prepared guerrilla forces in Syria and Lebanon to go to war. However, many PKK leaders were arrested in Turkey and sent to Diyarbakır Prison. Because of the treatment of the prisoners, the prison became the site of much political protest. (See also Torture in Turkey#Deaths in custody.)

In Diyarbakır Prison, PKK member Mazlum Doğan burned himself to death on 21 March 1982, in protest at the treatment in prison. Ferhat Kurtay, Necmi Önen, Mahmut Zengin and Eşref Anyık followed his example on 17 May. On 14 July, PKK members Kemal Pir, M. Hayri Durmuş, Ali Çiçek and Akif Yılmaz started a hunger strike in Diyarbakır Prison. In 1983, the conflict reached Iraqi Kurdistan as the Kurdistan Region–PKK conflict. Kemal Pir died on 7 September, M. Hayri Durmuş on the 12th, Akif Yılmaz on the 15th, and Ali Çiçek on the 17th. On 13 April 1984, a 75-day hunger strike started in Istanbul. As a result, four prisoners—Abdullah Meral, Haydar Başbağ, Fatih Ökütülmüş, and Hasan Telci—died.Report of the Human Rights Foundation of Turkey: File of Torture: Deaths in Detention Places or Prisons (12 September 1980 to 12 September 1995), Ankara, March 1996 , page 68

On 25 October 1986, the third Congress was held in Beqaa Valley, Lebanon. Issues raised included lack of discipline, growing internal criticism, and splinter groups within the organization. This had led the organisation to execute some internal critics, especially ex-members who had joined Tekosin, a rival Marxist–Leninist organization. Öcalan strongly criticized the leaders responsible for the guerrilla forces during the early 1980s and threatened others with the death penalty, if they joined rival groups or refused to obey orders. The PKK's military defeats meant they were no closer to their primary goal of an independent Kurdistan. Cooperation with criminals and dictators had tarnished the organization's image. During the Congress, the leaders decided to advance the armed struggle, increase the number of fighters, and dissolve the HRK, which was replaced by the Kurdistan Popular Liberation Army (ARGK). A newly established Mahsum Korkmaz Academy, a politico-military academy, replaced the Helve Camp, and a new military conscription policy was approved, which obliged every family to send someone to the guerrilla forces.

The decisions that were taken during the third Congress transformed the PKK from a Leninist organization into one in which power was more concentrated, as Öcalan accrued more Önderlik (leadership). Some of the reasons why Öcalan took power from the other leaders, such as Murat Karayilan, Cemil Bayik and Duran Kalkan, were growing internal conflict and the organization's inability to stop it. According to Michael Gunter, Öcalan, even before this time, had already carried out a purge of many rival PKK members, who were tortured and forced to confess they were traitors before being executed. Ibrahim Halik, Mehmet Ali Cetiner, Mehmet Result Altinok, Saime Askin, and Ayten Yildirim were some of the victims. Later in 2006, Öcalan denied these accusations and stated in his book that both Mahsum Korkmaz, the first supreme military commander of the PKK, and Engin Sincer, a high-ranking commander, likely died as a result of internal conflicts and described the perpetrators as "gangs". Leaked reports, however, revealed the authoritarian personality of Öcalan, who had brutally suppressed dissent and purged opponents since the early 1980s. According to David L. Philips, up to sixty PKK members were executed in 1986, including Mahsum Korkmaz, who he believes was murdered on 28 March 1986. Between the 1980 and 1990, the organization targeted defectors, assassinating two of them in Sweden, two in the Netherlands, three in Germany and one in Denmark.