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.

Greek PM Alexis Tsipras has announced he is stepping down and has called a snap election for Sept. 20, less than a year since he took office.