Knattleikr
Knattleikr (Old Icelandic for 'ball-game') was an ancient Norse ball game mentioned in the Sagas of Icelanders. Balls games of the kind are recorded from across the world (cf. Older Swedish: väderboll, lit. 'air ball', isboll, lit. 'ice ball'; English medieval football, hockey, etc.), and ultimately lead to various modern sports.
The term is also applied to a modern sport created by re-enactors, and now played at a few United States institutions as a college club sport, based on what is known about the historical game.