The victory of Gustavo Petro and running mate Francia Márquez in the final round of the Colombian presidential elections this June is perhaps the least likely result in the recent leftward swing across Latin America. Both Petro and Márquez are political outsiders in a country that has been the lynchpin of US power on the continent, and where the Left has never before held national power.

Petro is a former guerilla fighter with the M19 movement, which laid down arms in 1991. The 61-year-old has emerged as a popular figure on the Left and a highly successful mayor of the capital Bogotá, a job in which he was recognized for his efforts to tackle climate change. The 40-year-old Márquez is a former goldminer and live-in maid turned environmental campaigner, who won the Goldman prize for her work organizing against illegal mining. She is also from the mostly coastal African-Colombian community, which makes up about 10 per cent of the population but has never been represented in the upper echelons of national power. Most previous Colombian leaders were educated abroad and drawn from oligarchic families – Márquez, in contrast, used to sleep on a dirt floor.