"In the year following the invasion of Ial [i.e. in 1150], Owain Gwynedd and Madog came to blows. Though there is no record of the achievement, Owain seems about this time to have taken Rhuddlan Castle and made himself master of Tegeingl; accordingly, he and Madog met at Coleshill, once a manor of the Earl of Chester and miles away from the Welsh border, but now, as the star of Wales rose to the zenith, to be the battleground of the two Welsh leaders. The prince of Powys did not rely upon his own strength, but came into the field with the support of troops lent him by Earl Ranulf, who had good reasons of his own for wishing to check the progress of Owain. Nevertheless, it was Owain who won the day." Source: J.E.Lloyd, A History of Wales, vol II, 1912, p.494.
1150: In that year Madog ap Maredudd, king of Powys, with the help of Ranulf, earl of Chester, prepared to rise up against Owain Gwynedd. And after the people of his supporters had been slain at Coleshill, the others turned their backs in flight.
Source: Thomas Jones, The Chronicle of the Princes, 1955, p.129.
B.A.Malaws, RCAHMW, 31 August 2006.