Abdullah Ocalan, the founder of the Kurdistan Workers' Party (PKK), issued a historic call to the group to disarm as part of a new path towards a peace agreement with the Turkish state.
On a plane back to Turkey following his capture in 1999, Mr Ocalan said he loved his country and “would serve it if required.” Decades later, the group remains one of Turkey's major national security issues.
Here is a list of key dates in the conflict.
1974: The PKK was formed as a clandestine Marxist-Leninist group by left-leaning Kurdish students led by Mr Ocalan.
In 1978, it held its first congress at a teahouse near Diyarbakir, establishing itself as an organisation with the aim of creating an independent Kurdistan in the north-east of Turkey.
1982: The group established its first training camp in the Bekaa Valley with support of the Palestine Liberation Organisation (PLO).
August 1984: PKK carried out its first attacks in south-east Turkey, killing two soldiers. Fighting escalates over the following years and the group starts using bases in the Kurdish region of northern Iraq as refuge.
September 1998: Mr Ocalan flees his base in Syria after it signed the Adana Agreement with Turkey which committed Damascus to ending support for the group. PKK's main headquarters were also moved to the Qandil mountains of northern Iraq following the leader's departure from Syria.
February 15, 1999: Turkish special forces captured Mr Ocalan from Kenya. Bound and blindfolded, he was flown to Turkey.
June 1999: Mr Ocalan was tried and sentenced to death but the sentence was reduced to life imprisonment when Turkey abolished the death penalty in October 2002.
Following his capture, the PKK announced a unilateral ceasefire which ended in 2004.
2003: In an effort to work towards European Union membership, Turkey introduces legislative and constitutional reforms that increase Kurdish political and cultural rights, allowing for greater use of the Kurdish language. As prime minister, Turkish President Recep Tayyip Erdogan took a more liberal course with regards to the Kurds.
2010: Secret talks were held in Oslo between Turkish intelligence officers and PKK representatives. Talks break down.
Summer 2012: Fighting reaches new intensity. Turkish authorities round up Kurdish activists.
In October, Mr Ocalan and government representatives open talks while imprisoned Kurdish activists hold hunger strike. Kurdish militants end hunger strike in response to an appeal from Mr Ocalan the following month, opening way for talks.
March 21 2013: Mr Ocalan announces ceasefire and orders his fighters to withdraw from Turkish soil.
2015: The rise of ISIS in neighbouring Iraq and Syria led to the emergence of the YPG as a force fighting against the extremist group, taking control of areas near the Turkish border. Ankara views the YPG as the Syrian offshoot of the PKK.
In March, Mr Ocalan urged the PKK's leadership to disarm. The leadership in Qandil did not follow the call.
In July, the ceasefire collapsed, unleashing the bloodiest period in the conflict and resulting in extensive destruction in urban areas of south-east Turkey.
June 2020: After alleged attacks by the PKK on Turkish bases, Turkey launched Operations Claw-Eagle and Claw-Tiger, including air and land campaigns on the group in the Kurdish areas of Iraq. The operations spark criticism from the Iraqi government, labelling them an attack on the country's sovereignty. The Kurdistan Regional Government (KRG) also expressed concern over civilian casualties but neither Baghdad nor Erbil stop Ankara from continuing and mounting bases.
February 2021: Turkey sent a military mission to rescue 13 nationals captured by the PKK. It failed and all of the captives were found dead, with Ankara blaming their deaths on the PKK. The group said the captives were killed by Turkish bombing. A US State Department statement did not blame the PKK, increasing the rift between Ankara and Washington.
July 2024: Iraqi government announced a ban on the PKK and issued instructions for the group to be described as the "banned Kurdistan Workers' Party" in all official correspondence. It marked the most significant statement from Baghdad with regards to the PKK's status in the country. Iraq has not designated it a terrorist group.
October 2024: PKK claimed responsibility for an attack on a defence company near Ankara that killed five people and injured 22 others.