Complex sentence: He was rescued by Dónall Geimhleach Ó Catháin, the Scottish Covenanters landed an army in Ulster and drove the Irish Catholic forces out of the greater part of the province.
Split into simpler sentences: He was rescued by Dónall Geimhleach Ó Catháin. The Scottish Covenanters landed an army in Ulster and drove the Irish Catholic forces out of the greater part of the province.