Complex sentence: He came from a family which had a tradition of Crown service, and probably came from the north of England; he was probably a cousin of Laurence Minot, the poet, although very little is known of Laurence's life.
Split into simpler sentences: He came from a family which had a tradition of Crown service, and probably came from the north of England. He is thought to have been a cousin of Laurence Minot, the poet, although very little is known of Laurence's life.