Complex sentence: When the Irish Rebellion of 1641 broke out he was living at Finglas near Dublin; he brought his family to Dublin for safety, and the Crown quickly enlisted his services for the defence of Drogheda.
Split into simpler sentences: When the Irish Rebellion of 1641 broke out he was living at Finglas near Dublin. He brought his family to Dublin for safety, and the Crown quickly enlisted his services for the defence of Drogheda.