In this two-part series, Lyse Doucet tells the story of one of the biggest humanitarian crises of our age, the Syrian civil war - seven years of brutal conflict, surpassing the length of World War II. Lyse, who has reported on the conflict from the start, explores how peaceful protest for change spiralled into unspeakable savagery - half a million people killed, millions of lives shattered and so much of Syria in utter ruins.

The series tells the inside story of the war from multiple perspectives. It hears accounts of the experiences of Syrian people from different sides - civilians and fighters who stayed loyal to the government of President Assad, as well as those who rebelled. To gain greater understanding of how this catastrophe unfolded, Lyse also speaks to leading politicians and soldiers from within Syria and also from western and regional powers, including John Kerry, David Petraeus, General Lord David Richards and William Hague.