2015 has been a dramatic year in elections around the world: old leaders were toppled, upstarts and novices seized the helm, and embattled governments somehow managed to cling on. Here, the experts who covered them take stock of what’s happened—and look at what’s in store for 2016.

Nigerians have chosen General Muhammadu Buhari, a former military ruler, over incumbent Goodluck Jonathan, to be their president.