Complex sentence: After several years spent travelling, and a period as a soldier in the Dutch army, he returned to England and lived quietly till 1646, when he was appointed to accompany King Charles I, who was being taken from Newcastle as a prisoner.
Split into simpler sentences: After several years spent traveling, and a period as a soldier in the Dutch army, he returned to England where he lived quietly till 1646. He was then appointed to accompany King Charles I, who was being taken from Newcastle as a prisoner.