Complex sentence: Walter married Bethóc, daughter of Gille Críst, Earl of Angus and his wife Marjorie, said to be a daughter of Henry of Scotland, 3rd Earl of Huntingdon.
Split into simpler sentences: Walter married Bethóc, daughter of Gille Críst, Earl of Angus and his wife Marjorie. Marjorie was reportedly a daughter of Henry of Scotland, 3rd Earl of Huntingdon.