Iraq’s 2005 Constitution recognises an autonomous Kurdistan region in the north of the country, run by the Kurdistan Regional Government.
This was the outcome of decades of political and military efforts to secure self-rule by the Kurdish minority, who are estimated to number more than 6 million and make up between 17% and 20% of the population of Iraq.
Kurds, who number 30-40 million in total, live in a compact area that reaches from Syria in the west to Iran in the east and Iraq in the south, north through Turkey, and into the states of the former Soviet Caucasus.
Only in Iraq have they managed to set up a stable government of their own in recent times, albeit within a federal state.
However, the increase of sectarian tensions within Iraq as a whole from 2013 onwards, culminating in a campaign of violence launched by the Al-Qaeda-affiliated Islamic State of Iraq, meant that by 2014 the unity of Iraq was under severe threat.
In July 2014, Iraqi Kurdistan President Massoud Barzani announced that his government planned to hold a referendum on independence later in the year, given that Iraq was already “effectively partitioned”. The announcement triggered alarm among Iraq’s neighbours, who feared that it could set a precedent for their own restive Kurdish minorities.
But a change of leadership in the Iraqi government was followed by improved relations with Iraqi Kurdistan. The two sides agreed to work together to defeat the common enemy of Islamic State and plans for an independence referendum were put on hold.
The Kurds of Iraq came under British colonial rule after the defeat of the Ottoman Empire in 1918. Frustrated in their hopes for independence, Kurdish leaders launched a series of rebellions against British and subsequent Iraqi rule.
These were put down ruthlessly, most notoriously in the late 1980s when Saddam Hussein attacked the Kurds with massed armed forces in the ‘Anfal’ campaign.
This involved the deliberate targeting of civilians with chemical weapons, most notoriously in the town of Halabja in 1988.
Various Iraqi governments promised autonomy to the Kurds after the 1958 revolution, but none came to fruition until the anti-Saddam international coalition established a partial no-fly zone in northern Iraq in 1991 after the first Gulf War.
This allowed Kurdish leaders and their Peshmerga armed forces to consolidate their hold on the north after Iraqi forces withdrew, and provided the basis for the 2005 constitutional settlement.
The immediate tasks facing the Kurdish government were great, and included rebuilding infrastructure, creating an administration and absorbing hundreds of thousands of displaced people after years of war and destruction.
Overall its efforts exceeded all expectations. Iraqi Kurdistan largely escaped the privations of the last years of Saddam’s rule and the chaos that followed his ouster in 2003, and built a parliamentary democracy with a growing economy.
Major problems remain, nonetheless. The landlocked Kurdistan Region is surrounded by countries unsympathetic to Kurdish aspirations, like Turkey and Iran, and by states approaching internal collapse – Syria and the rest of Iraq.
It is also in dispute with the Iraqi government over several territories, in particular the historic city of Kirkuk. No agreement has been reached over Kirkuk, but in the summer of 2014, when the city was in danger of falling to the hard-line Sunni Islamists of ISIS (Islamic State in Iraq and the Levant), Kurdish Peshmerga forces pre-empted this by seizing Kirkuk themselves.
Tension between the main political parties – the Patriotic Union of Kurdistan and the Kurdistan Democratic Party – erupted into a civil war that almost destroyed the autonomous government in 1994-97, and some differences remain.
All copyrights for this article are reserved to bbc middle east