ROME -- Syrians marked seven years since a popular uprising sparked their country's vicious civil war by fleeing one of the hardest hit regions.

Carrying what they could, thousands took advantage of the lull in the fighting Thursday and streamed out of Ghouta, straight past the Syrian army that has been bombing their neighborhoods relentlessly.

We got as close as we could inside Eastern Ghouta earlier this month. It was on the front line of the assault on the rebel-held stronghold.

The toll from the war is staggering: more than 400,000 people killed or missing, more than 1 million injured and more than half of the population -- 12 million people -- forced to flee their homes.

It's hard to remember that this started with peaceful demonstrations against the government, but the crackdown was swift, deadly and quickly spiralled into a civil war.

President Bashar Assad, backed by Russia and Iran, has stopped at nothing to stay in power, including using chemical weapons against his own people.

The Islamic State of Iraq and Syria (ISIS) and other extremist groups have thrived in the chaos, pulling the U.S. military into the crisis.

Seven years on, it's no longer a civil war, but a world war, and it's one with no end in sight.