Over the past eight years, it’s thought that about half a million Syrians have been killed and many more have been injured.
The conflict has led to more people having to flee their homes than in any other crisis of our time.
For the past few years, BBC News has been following the story of one little boy, Mustafa, whose parents were both killed in an attack which also gave him life-changing injuries.
Caroline Hawley went to meet with Mustafa again at his new home in Jordan.
Producer: Cara Swift
Camera and editing: David McIlveen