Complex sentence: He was the son of Gerald de Windsor, Constable of Pembroke Castle and Nest, a Welsh princess and former mistress of Henry I. He fought under Robert FitzMartin at the Battle of Crug Mawr in 1136.
Split into simpler sentences: He was the son of Gerald de Windsor, Constable of Pembroke Castle. His mother was Nest, a Welsh princess and former mistress of Henry I. He fought under Robert FitzMartin at the Battle of Crug Mawr in 1136.