Kurds make up 15-20 percent of the country's population -- some five to six million people -- and live mostly in the oil-rich north.

Significant populations of Kurds, a people of Indo-European origin who are mainly Sunni Muslims, also live in Turkey, Iran and Syria.

- First uprising -

The fight for a Kurdish state, which started during Britain's mandate in Iraq, was relaunched in 1961 by the Kurdistan Democratic Party (KDP) of Mustafa Barzani, founded in 1946.

In March 1970 Iraq's ruling Baath Party agreed to the creation of a Kurdish region. But four years later fighting erupted again as a peace deal broke down.

- Split -

In 1975 the Algiers accords, aimed at ending a border conflict between Tehran and Baghdad, resulted in Iraq's Kurds losing the support of Iran. The Kurdish rebellion collapsed.

The KDP split with the creation by Jalal Talabani of the revolutionary Patriotic Union of Kurdistan (PUK).

- Anfal -

In 1987, as the Iran-Iraq war neared its end, the regime launched violent operations against the Kurds. The Anfal campaign saw nearly 180,000 Kurds killed and more than 3,000 villages destroyed.

The regime's policy of "Arabisation" forced thousands of Kurds to leave their homes, to be replaced by Arabs.

Baghdad used chemical weapons against the village of Halabja, killing 5,000 people.

- De facto autonomy -

Iraqi Kurdistan gained de facto autonomy after the 1991 Gulf War over Kuwait, when Western powers intervened to protect Kurds against an onslaught by Saddam's forces that led hundreds of thousands to flee to neighbouring countries.

The United States and its allies set up no-fly zones in southern Iraq and the northern, Kurdish-majority region.

In 1992 the Iraqi Kurds elected a parliament and set up a government. The KDP controlled the north of the region up to the Turkish border while the PUK controlled the south, up to the Iranian border.

- Fratricidal war -

However, in 1994 the PUK and the KDP clashed over the distribution of the territory's resources, particularly over taxes imposed by the KDP on border traffic with Turkey. The unrest left 3,000 dead in four years.

In 1998 Massud Barzani and Talabani, meeting in Washington, signed an accord aimed at settling their differences.

In 2002 they reached a peace accord reinstating a unified parliament.

- Autonomy -

In 2003 Talabani and Barzani buried the hatchet as the Kurds allied with American troops in their war to overthrow Saddam.

Iraqi Kurdistan, whose capital is Arbil, was transformed into an autonomous region under the 2005 Constitution, which set up a federal republic.

In April that year, Talabani became president of Iraq, then in June, the Kurdish parliament elected Barzani as Kurdish president. In January 2006 they agreed to set up a single administration.

Talabani died this month in Germany, barely a week after an Iraqi Kurdish vote for independence.

- Crisis -

In June 2014, Iraqi Kurdish peshmerga forces took control of oil-rich Kirkuk after federal forces withdrew in the face of an offensive by the jihadist Islamic State group.

Benefitting from the disarray of the Iraqi army in the first months of the lightning IS offensive, Kurdish fighters went on to take control of several northern territories, particularly in Kirkuk province.

On September 25, 2017, Iraqi Kurds voted overwhelmingly for independence in a vote slammed by Baghdad as unconstitutional.

On October 15 government troops launched an operation to reinstate the central government's authority in the disputed province of Kirkuk.

According to officials, their advance has been helped by the fact that PUK forces withdrew of their own will under the terms of an accord with Baghdad.