Complex sentence: Her maternal grandfather was David Greer, an RIC sergeant in Castlewellan, County Down, Northern Ireland who, in the 1880s, later became a land steward to the Annesley family, the wealthy landlords who built the town of Castlewellan.
Split into simpler sentences: Her maternal grandfather was David Greer, an RIC sergeant in Castlewellan, County Down. In the 1880s he became a land steward to the Annesley family, wealthy landlords who built the town of Castlewellan.