Complex sentence: The rebel leader Aske and his men came to Wressell, where he was ill in bed, and asked Percy to resign his commands of the marches into the hands of his brothers, or at least go over to the rebels.
Split into simpler sentences: The rebel leader, Aske, and his men came to Wressell, where he was ill in bed. The earl, who is spoken of as "Crasyside," was besought to resign his commands of the marches into the hands of his brothers, or at all events go over to the rebels.