♤ More than 400,000 people have been killed in this civil war.

♤ In August 2013, it was reported that chemical weapons were used in the war in Syria, which caused anger around the world. Both the rebels and the Syrian government denied that they were responsible.

♤ In September 2013, Russia and the US reached an agreement which said the Syrian government should give up its chemical weapons and destroy them so they can never again be used. This was important as Russia and the US support different sides in the Syrian war.

♤ The process of destroying the weapons began in October 2013 and the people working on this project, monitors from the Organisation for the Prohibition of Chemical Weapons (OPCW) were awarded the Nobel Peace Prize later that month.

♤ But in April 2017, there was reportedly another chemical weapons attack on a town in north-west Syria, which killed and injured many people. This was denied by the Syrian government as well as Russia.

♤ The US has responded with military action by carrying out missile attacks on Syria, which the UK has said it supports.

♤ IS had taken over large parts of Iraq and then moved into eastern Syria. In the chaos of the war they were able to gain land and power there too.

♤ Raqqa was the first big city captured by IS in Syria in early 2014. The group went on take over large parts of the country towards Aleppo in the north, and along the Turkish border.