Complex sentence: The eldest daughter of Henry of Grosmont, 1st Duke of Lancaster and Earl of Leicester, and his wife Isabel de Beaumont, she was born at Bolingbroke Castle in Lindsey.
Split into simpler sentences: The eldest daughter of Henry of Grosmont, 1st Duke of Lancaster and Earl of Leicester, and his wife Isabel de Beaumont. She was born at Bolingbroke Castle in Lindsey.