Zürcher Nachrichten - Key stages in the war against IS

In neighbouring Iraq, government forces have also launched an offensive to recapture Fallujah, a key IS stronghold west of Baghdad.

The first air strikes

On August 8, 2014, US jets strike IS positions in northern Iraq in response to an appeal from Baghdad, in the first American military operation in the country since troops withdrew in late 2011.

Already entrenched in neighbouring Syria, IS seized swathes of Iraqi territory in a lightning offensive launched in June 2014 and marked by a complete collapse of the security forces.

On September 5, US President Barack Obama vows to build an international coalition to defeat IS.

On September 23, the US and Arab allies launch air strikes on IS in Syria.

IS driven out of Kobane

IS is driven out of the Syrian border town of Kobane on January 26, 2015 after more than four months of fighting led by Kurdish forces backed by coalition air strikes.

An Iraqi military official also says the eastern province of Diyala has been liberated.

Iraq's Tikrit recaptured

On March 31, 2015, Baghdad announces the "liberation" of Tikrit, 160 kilometres (100 miles) north of Baghdad. Government forces and Shiite militias had launched their offensive on March 2 against the IS, which controlled Tikrit for nearly 10 months.

But in May, the IS takes Iraqi provincial capital Ramadi, and Syria's famed ancient city of Palmyra, a UNESCO World Heritage site.

IS ousted from border town

On June 16, 2015, Kurdish militia backed by Syrian rebels and coalition air strikes seize the town of Tal Abyad on the Syrian border with Turkey from IS, which had occupied it for more than a year.

Tal Abyad was one of two main transit points on a key supply route to de facto IS capital Raqa.

Turkey declares war on IS

On July 24, 2015, Turkish warplanes bomb IS positions inside Syria for the first time in a dramatic toughening of Ankara's stance.

Turkish raids are nonetheless mostly aimed at positions of the Kurdistan Workers Party in Iraq and Syria.

Turkey gives Washington the go-ahead to conduct operations over Syria from Ankara's strategic southeastern air base of Incirlik.

Russia intervenes in Syria

On September 30, 2015, Russia launches air strikes in Syria to help its Damascus regime ally, but Washington accuses Moscow of targeting US-backed Syrian rebels rather than IS fighters.

Iraq's Sinjar, Ramadi retaken

On November 13, 2015, Iraqi Kurds announce the "liberation" of Sinjar from IS in an assault that severs a key jihadist supply line with Syria. Across the border, a coalition of Arab and Kurdish fighters drives IS out of the village of Al-Hol, also on the supply route. The US-led coalition provides air support.

Iraqi forces retake Ramadi on December 27.

Syrians retake Palmyra

On March 27, 2016, Syrian forces backed by Russia retake Palmyra.

Two-pronged offensive begins

On May 24, Kurdish and Arab units grouped within the Syrian Democratic Forces (SDF) launch an assault backed by US-led air support against IS fighters north of Raqa, but makes no mention of the city itself. Russia, which appears to have suffered an IS attack on one of its air bases in Syria, says it is ready to coordinate actions with both the US and SDF.

In Iraq, IS fighters in Fallujah were besieged by government troops and paramilitary units.

IS showed it could still strike back, with a wave of attacks killing more than 160 people a day earlier in Syrian regime coastal strongholds.

US tally of IS retreats

On May 16, a Pentagon spokesman says the IS has lost about 45 percent of its territory in Iraq, and between 16-20 percent of land it seized in Syria.

G.Kuhn--NZN