Complex sentence: Brychan's eldest son, Rhain Dremrudd, founded a dynasty which ruled the kingdom uninterrupted until the mid 7th century, when the inheritance of a woman, Ceindrych, brought the kingdom into the hands of Cloten of Dyfed and Brycheiniog.
Split into simpler sentences: Brychan's eldest son, Rhain Dremrudd, founded a dynasty which ruled the kingdom uninterrupted until the mid 7th century. In the 7th century, the inheritance of a woman, Ceindrych, brought the kingdom into the hands of Cloten of Dyfed and Brycheiniog.