Complex sentence: In the period before Ruaidrí ua Canannáin rose to prominence, the Cenél nEógain heir apparent to the High Kingship, Muirchertach mac Néill, was killed in battle in 943, while the High King, Donnchad Donn of Clann Cholmáin, died the following year.
Split into simpler sentences: In the period before Ruaidrí ua Canannáin rose to prominence, the Cenél nEógain heir apparent to the High Kingship, Muirchertach mac Néill, was killed in battle in 943. The High King, Donnchad Donn of Clann Cholmáin died the following year.