Complex sentence: Morgan p.86-87 He was the youngest son Hugh O'Neill, Earl of Tyrone who had initially been a supporter of the Crown but led Tyrone's Rebellion between 1594-1603 before he made peace and was restored to royal favour at the Treaty of Mellifont.
Split into simpler sentences: Morgan p.86-87 He was the youngest son of Hugh O'Neill, Earl of Tyrone who had initially been a supporter of the Crown but led Tyrone's Rebellion between 1594-1603. He then made peace and was restored to royal favour following the Treaty of Mellifont.