The Peshmerga's history dates back to the 18th century, when they began as a tribal paramilitary border guard under the Ottoman Turks and the Safavid kurds.

Though unifying and integrating the Peshmerga has been on the Kurdistan Region's public agenda since 1992, the individual forces remain divided due to factionalism, which has proved to be a major stumbling block.

[28] Following the 2003 invasion of Iraq, the Peshmerga played a key role in helping the United States on the mission to capture deposed Iraqi president Saddam Hussein.

The word "Peshmerga" can be translated to "to stand in front of death",[34][35][36] and Valentine states it was first used by Qazi Muhammad in the short-lived Mahabad Republic (1946–47).

[40][41] After the fall of the republic and the execution of head of state Qazi Muhammad, Peshmerga forces reemerged as guerrilla organizations that would go on to fight the Iranian and Iraqi governments for the remainder of the century.

Jalal Talabani, a leading member of the KDP, left the same year to revitalize the resistance and founded the Patriotic Union of Kurdistan.

This event created the baseline for the political discontent between the KDP and PUK that divides Peshmerga forces and much of Kurdish society in Kurdistan.

[41] As tension increased between KDP and PUK, most Peshmerga fought to keep a region under their own party's control while also fighting off Iraqi Army incursions.

[45] The civil war officially ended in September 1998 when Barzani and Talabani signed the Washington Agreement establishing a formal peace treaty.

[48] In 2014, the Peshmerga withdrew from the Nineveh Plains which was said by the locals as being a contributing factor of the quick Islamic State victory in the invasion, and the widespread massacre of Yazidis, who were rendered defenseless.

Following the events of the Iraqi Civil War in 2014, the United States and several Europe nations pressured the PUK and KDP to set up mixed brigades of Peshmerga as a condition for aid and funding.

[50] However, officers continue to report to and take orders from their party leaders who also control the deployment of forces loyal to them and appoint front-line and sector commanders.

[76] In 2015, for the first time, Peshmerga soldiers received urban warfare and military intelligence training from foreign trainers, the Combined Joint Task Force – Operation Inherent Resolve.

[50] This became apparent during the Islamic State offensive in 2014 where the Peshmerga found itself lacking ambulances and frontline field hospitals, forcing wounded fighters to walk back to safety.

[27] During the Iraqi–Kurdish conflict the majority of women served within the Peshmerga in supporting roles such as building camps, taking care of the wounded, and carrying munitions and messages.

[27] In the months leading up to the 2003 U.S. invasion of Iraq, the United States launched Operation Viking Hammer which dealt a huge blow to Islamic terrorist groups in Iraqi Kurdistan and uncovered a chemical weapons facility.