The Laiginians arrived in Connacht in the 3rd century AD from Leinster, conquering the ruling Fir Bolg and Fomorians, and ruling until conquered by the Gael under the Connachta in the 5th century.
In the 3rd century AD, the Laiginians migrated to Connacht from Leinster, overthrowing the existing power of the Fir Bolg and Fomorians. They ruled Connacht until they were defeated by the Gaels under the Connachta in the 5th century.