Complex sentence: He then advanced against the Lancastrians, and having his life saved on the battle field by the Welsh Knight Sir David Ap Mathew, defeated them in the exceptionally bloody Battle of Towton in Yorkshire on 29 March 1461.
Split into simpler sentences: He then advanced against the Lancastrians, having his life saved on the battlefield by Welsh Knight Sir David Ap Mathew. He defeated them in the exceptionally bloody Battle of Towton in Yorkshire on 29 March 1461.