Age of Empires II, released in 1999, made monks a memorable part of its strategy gameplay because they could convert enemy soldiers and villagers instead of fighting them. The chant that accompanies conversion, widely known online as wololo, became a running joke among players and later spread through gameplay videos, streams and memes. Its popularity has lasted because the sound is instantly recognisable even to people who have never played the game, and it neatly stands in for any moment of persuasion, recruitment or sudden loyalty change.