- Financially strapped -

Situated in the rugged, mountainous north of Iraq, the region is home to about five million people.

It is mainly made up of Kurds, who are mostly Sunni Muslims, alongside Christian and Turkmen minorities, and comprises Arbil, Dohuk and Sulaimaniyah provinces.

The region was already economically strapped, due to the fall in the price of oil, its main resource, and has seen its oil revenues slashed by half.

In the wake of the September 25 referendum, government forces have seized back disputed territory, including oil-rich Kirkuk province.

- War against IS -

Kurdish forces have played a significant role in the war against the Islamic State group, and have been an important ally of the US-led coalition against the jihadists.

They took part in the massive operation to retake Mosul from IS, which was launched in October 2016, capturing territory near the city but stopping short of entering it.

The region has also taken in hundreds of thousands of people driven from their homes by the jihadists.

- Autonomy since 1991 -

Iraqi Kurdistan, whose capital is Arbil, became formally autonomous in 2005 under the constitution which set up a federal republic.

But it had gained de facto autonomy after the 1991 Gulf War over Kuwait when Western powers intervened to protect Kurds against an onslaught by the forces of Iraqi dictator Saddam Hussein that led hundreds of thousands to flee to neighbouring countries.

The United States and its allies set up no-fly zones in north and south Iraq, with the former helping to shield the Kurds.

Elections in 1992 established the regional parliament, with seats split between the Kurdistan Democratic Party (KDP) and the Patriotic Union of Kurdistan (PUK).

Disputes between the two parties led to deadly clashes between 1994 and 1998. Kurds then joined US troops in 2003 to help overthrow Saddam.

The Iraqi Kurds have kept their dialects, their traditions and a clan-based organisation, with regional politics dominated by two main families.

Massud Barzani, the leader of the KDP who was elected president of Kurdistan in 2005, remained in power despite the expiration of his term amid criticism from the opposition.

- Independence referendum -

Barzani declared on February 3, 2016 that the "time has come" for the country's Kurds to hold a referendum on statehood.

Despite weeks of threats and warnings, the non-binding plebiscite went ahead on September 25, 2017.

It was held in the three provinces of Iraqi Kurdistan as well as in disputed border areas such as the oil-rich province of Kirkuk.

Baghdad said the vote was "illegal".

The official results released on September 27 showed nearly 93 percent of voters back statehood. Turnout was over 72 percent.

In mid-October, the Iraqi army retook Kurdish-held positions outside its three regions over which it has extended its control since 2003, around the provincial capital of Kirkuk.

Iraq's supreme court declared the referendum unconstitutional on November 20.

- Barzani stands down -

Barzani told parliament on October 29 in a letter he was stepping down as president of the autonomous Kurdish region from November 1. His presidential functions had been frozen by parliament following the referendum's failure.

His nephew, Nechervan Barzani, has since been running Iraqi Kurdistan.