Advised by Jonathan Powell, former British Prime Minister Tony Blair's chief of staff, who negotiated the Northern Ireland agreement, Juan Manuel Santos, Colombia's President, has staked his presidency on a Yes vote ending the last remaining war in the Western hemisphere. "How much pain and tears, how much mourning and pointless plunder to finally conclude that war is not the way to solve this," he said.
The six-point plan promises political participation for Farc, truth and reconciliation tribunes, punishment for severe crimes, and land rights for rural communities. Powell said the deal could be a model for future conflicts - even Syria - adding: "It sets a real precedent for the rest of the world".
Final polling before the referendum showed 55 per cent of Colombians voting Yes, and 36.6 per cent voting No.
But the referendum has caused deep divisions - even within families.
Ferley Ruiz was 13 when the paramilitaries took him away. Now 31 and studying business administration at university in Bogota, he is voting Yes to peace with Farc - despite his four frightening years as a child soldier and the fact the group killed his sister.
"My mother called me after the signing and said: 'They think they can say sorry and it's all suddenly okay,"' he said. "I was surprised I suppose, because I thought she had got over it."
Maria del Rosario Guerra and her brother Antonio are both senators. But Guerra, 61 - six years older than his sister - has campaigned for Yes, his sister for No.
"It's a trap," Maria del Rosario Guerra said. "This referendum won't give us peace - it's the Government on its knees to give in to the Farc. Would the United States give in to al-Qaeda? Would Mexico give in to El Chapo?"