Battle for Iraq and Syria in maps
- 30 September 2015
- From the section Middle East
The rapid advance across Syria and Iraq by militant fighters from Islamic State (IS) in 2014 threw the region into chaos and led to US air strikes against their key positions.
The jihadist group, which has fighters from across the world, announced the establishment of a "caliphate" - an Islamic state - stretching from Aleppo in Syria to the province of Diyala in Iraq.
The US went on to assemble a coalition to fight the militants, which has launched more than 4,360 air strikes against IS targets in Iraq since the campaign began on 8 August 2014. The UK launched its first air strikes on 30 September 2014.
In neighbouring Syria, the US, along with Bahrain, Jordan, Qatar, Saudi Arabia and the United Arab Emirates, has also carried out more than 2,400 attacks on IS-held areas since 23 September 2014.
US President Barack Obama has warned his coalition allies they are facing a "long-term campaign".
Which countries are carrying out air strikes?
To date, the US has undertaken nearly all of the airstrikes in Syria.
In Iraq, other countries have played more of a role - but their contributions are still dwarfed by that of the US. The UK defence secretary Michael Fallon says the RAF has killed about 330 IS fighters in air strikes since 2014.
Militants from abroad
The US Central Intelligence Agency believes IS may have up to 31,000 fighters in the region, many of whom are foreign recruits.
Figures from the London-based International Centre for the Study of Radicalisation and Political Violence (ICSR) and the New York-based Soufan Group show an estimated 20,000 fighters from almost 80 countries have travelled to Syria and Iraq to fight with extremist groups.
The figures suggest that while about a quarter of the foreign fighters are from the West, the majority are from nearby Arab countries, such as Tunisia, Saudi Arabia and Jordan and Morocco.
As well as establishing a de facto capital of the caliphate in the Syrian city of Raqqa, Islamic State has inflicted a series of embarrassing defeats upon Iraqi forces over the past year.
The Iraqi city of Ramadi, in Anbar province, was seized by IS in May, forcing thousands of civilians to leave. An Iraqi offensive to recapture the city, supported by Shia militias, Sunni tribal fighters and US-led coalition air strikes, has made slow progress.
Tikrit was held for eight months by IS before Shia militias helped recapture of Tikrit the city in April. The Iraqi government declared a "magnificent victory" over Islamic State militants after a month-long operation.
Strategic importance of Kobane
Another battleground has been the fight for the Kurdish town of Kobane, on the border between Syria and Turkey.
Thousands of residents were forced into Turkey to flee the fighting, while coalition airstrikes targeted the advancing Islamic State fighters.
After months of fighting, in which about 1,600 people died, US Central Command announced in January 2015 that Kurdish forces controlled 90% of the town.
In June 2015, the Kurdish fighters known as the People's Protection Units (YPG) announced they had seized control of Tal Abyad, a border town to the east, from IS. The move was seen as key to securing the main road south to IS's headquarters in Raqqa.
It also extends the gains by the YPG across the north of the country.
Palmyra ancient ruins
Another key target taken by the militants has been Palmyra. IS captured the city, which includes a Unesco World Heritage site, in May 2015 and has gone on to destroy a number of its most famous antiquities including its two main temples and three funerary towers.
Syrian government war planes launched a series of attacks on IS positions using weapons supplied by its ally, Russia, in September.
Islamic State targeted a number of Iraqi dams during the early stages of their advance, in April 2014, capturing the facility at Falluja. They went on to take Mosul dam in August 2014, before US air strikes helped force them out later that month.
IS fighters also attacked the country's second largest dam at Haditha, but the area was secured by Iraqi forces In September 2014.
IS also gained control of much of the oil infrastructure in Iraq and Syria.
These refineries and the fields supplying them with oil have played a vital role in fuelling IS military units and in generating revenue for the group. The coalition has targeted these locations in an attempt to damage IS capabilities.
Iraq's key dams
Oil infrastructure across Syria and Iraq
More than four million people have fled abroad to escape the fighting in Syria. Most have gone to Lebanon and Turkey - but a significant number have also gone to Iraq.
Syrian refugees have put pressure on local services and infrastructure in Iraq - which is also having to cope with the return of many Iraqi refugees from Syria.
In addition, the UN estimates there are more than three million Iraqis who have been forced to leave their homes to escape the conflict and are displaced within the country or elsewhere.