Complex sentence: Meanwhile, the Dál nAraidi where still resisting the encroaching Northern Uí Néill and in 681, Dúngal Eilni, king of the Dál nAraidi, and his ally Cenn Fáelad of Ciannachta were killed at Dún Cethirinn.
Split into simpler sentences: Meanwhile, the Dál nAraidi where still resisting the encroaching Northern Uí Néill. In 681, Dúngal Eilni, king of the Dál nAraidi, and his ally Cenn Fáelad of Ciannachta were killed at Dún Cethirinn.