Wikipedia
McCaul, McCall, and MacCawell is an Irish surname, derived from the Gaelic Mac Cathmhaoil, meaning the "son of Cathmhaol", descendant of being implied. The name Cathmhaoil itself is derived from cath mhaol meaning "battle chief". The Mac Cathmhaoil were the leading family of Cenél Fearadhaigh, of the Uí Néill, and were based around Clogher in modern-day County Tyrone, Northern Ireland. They were one of the seven powerful septs that supported the O'Neills. The name is now rare in Ulster as it has been Anglicised under various different forms such as, Campbell, McCawl, Caulfield, McCall, Alwell, Callwell, McCowell, McCuill, Howell, MacHall, and McQuade.
The height of their power was in the 12th century where their territory covered most of modern County Tyrone, and deep into County Fermanagh. By the mid fourteenth century their power in Fermanagh, was broken by the rise of the Maguires. Having controlled the seat of power of the diocese of Clogher, the MacCawells provided many abbots, deans, canons etc. to it and neighbouring dioceses including two bishops. By the end of the sixteenth century there appears to have been a large migration of the sept into the modern counties of Down and Armagh.