Complex sentence: Agravain is the second son of King Lot of Orkney and Lothian and Morgause and brother to Gawain, Gaheris, Gareth, and Mordred.
Split into simpler sentences: Agravain is the second son of King Lot of Orkney and Lothian and Morgause. He is brother to Gawain, Gaheris, Gareth, and Mordred.