sentences:  In the late fourth century there was an influx of settlers from southern Ireland, the Uí Liatháin and Laigin (with Déisi participation uncertain), arriving under unknown circumstances but leaving a lasting legacy especially in Dyfed.It is possible that they were invited to settle by the Welsh.There is no evidence of warfare, a bilingual regional heritage suggests peaceful coexistence and intermingling, and the "Historia Brittonum" written c. 828 notes that a Welsh king had the power to settle foreigners and transfer tracts of land to them.