The Motte is the first thing that the Normans would have built when they arrived here about 1170. At that time it probably had a wooden castle on top. Over the years this would have rotted away. Newcastle Lyons means the new castle of Liamhain.

This motte was surrounded by a bailey. The bailey was built by digging a trench all around the motte, piling up the earth and putting timber stakes on top of the earth. People could run here for protection for themselves and their cattle and horses if the Irish attacked them.

The native chief of Liamhain at the time the Normans built the Motte was McGiolla Mocholmog. He later made a deal with the Normans and was allowed to rule this area again. However, in 1215 his nephew and heir lost all this land when the King of England took it for himself and Newcastle became a Royal Manor.