Complex sentence: He left Ireland upon the revolution, and entered St. John's College, Cambridge; graduated B.A. there in 1691, and subsequently returned to Dublin, where he proceeded B.A. in 1693 and M.A. two years afterwards.
Split into simpler sentences: He left Ireland upon the revolution, and entered St. John's College, Cambridge, graduating B.A. there in 1691. He subsequently returned to Dublin, where he proceeded B.A. in 1693 and M.A. two years afterwards.