The Battle of Badon (Latin: bellum Badonis, Latin: Obsessio Montis Badonici), also known as the Battle of Badon Hill or Mount Badon (Latin: bellum in monte Badonis; Modern Welsh: Mynydd Baddon), is a battle thought to have occurred between a force of Britons and an Anglo-Saxon war band in the late 5th or early 6th century. Chiefly known today for the supposed involvement of King Arthur, it is credited in medieval British and Welsh sources as a major political and military event but seems to have passed unremarked in the Anglo-Saxon histories. Because of the limited number of sources, there is no certainty about the date, location, or details of the fighting.^[2][3]

• http://en.wikipedia.org/wiki/Battle of Mons Badonicus