Complex sentence: Richard de Clare, 2nd Earl of Pembroke (of the first creation), Lord of Leinster, Justiciar of Ireland (1130--20 April 1176) was an English lord notable for his leading role in the Norman invasion of Ireland.
Split into simpler sentences: Richard de Clare, 2nd Earl of Pembroke (of the first creation), Lord of Leinster, Justiciar of Ireland (1130--20 April 1176). He was an English lord notable for his leading role in the Norman invasion of Ireland.