It was recorded in 940 that King Muirchertach of the Leather Cloaks and his forces, found that Cretshalach, as it was then known, was the worst passageway during their Circuit of Ireland. In ancient times the passageway through Cratloe ran over a steep hill, and was the main route from Munster into Connacht. The army stayed the night on top of the mountain where High King Crimthann was murdered, Sliabh-Suidhe-an-riogh, or in English, The Mountain Of The Death Of The King.