Dick the Third lost his kingdom, of course
The one he tried to trade for a horse
And House Plantagenet
At Bosworth its end met
Henry Tudor took his crown by force

Event: The Battle of Bosworth Field, the last significant battle of the Wars of the Roses, which saw the end of the Plantagenet Dynasty (through the death of Richard III) and the rise of the Tudor Dynasty
Year: 1485
Learn more: http://en.wikipedia.org/wiki/Battle_of_Bosworth_Field