The Peshmerga comprise the standing military of Kurdistan Region, an autonomous political entity within the Republic of Iraq. According to the Constitution of Iraq, the Peshmerga and their security subsidiaries are solely responsible for the security of Kurdistan Region, chiefly due to the fact that the Iraqi Armed Forces are forbidden to enter Iraqi Kurdistan. These subsidiaries include Asayish, Parastin û Zanyarî, and Zêrevanî. The Peshmerga's history dates back to the 18th century, when they began as a strictly tribal pseudo-military border guard under the Ottoman Turks and the Safavid Iranians. By the 19th century, they had evolved into a disciplined and well-trained guerrilla force.

Kurdistan Region is an autonomous administrative entity within the Republic of Iraq. It comprises four Kurdish-majority divisions of Arab-majority Iraq: the Erbil Governorate, the Sulaymaniyah Governorate, the Duhok Governorate, and Halabja Governorate. The KRI is bordered by Iran to the east, by Turkey to the north, and by Syria to the west. It does not govern all of Iraqi Kurdistan, and lays claim to the disputed territories of northern Iraq; these territories have a predominantly non-Arab population and were subject to the Ba'athist Arabization campaigns throughout the late 20th century. Though the KRI's autonomy was realized in 1992, one year after Iraq's defeat in the Gulf War, these northern territories remain contested between the Kurdistan Regional Government and the Government of Iraq to the present day. In light of the dispute, the KRI's constitution declares the city of Kirkuk as the capital of Iraqi Kurdistan. However, the KRI does not control Kirkuk, and the Kurdistan Region Parliament is based in Erbil. In 2014, when the Syria-based Islamic State began their Northern Iraq offensive and invaded the country, the Iraqi Armed Forces retreated from most of the disputed territories. The KRI's Peshmerga then entered and took control of them for the duration of the War in Iraq (2013–2017). In October 2017, following the defeat of the Islamic State, the Iraqi Armed Forces attacked the Peshmerga and reasserted control over the disputed territories.