he was the son of john spring (d.1601) and his wife mary (or anne) trelawney. he was the grandson of sir william spring of lavenham and his first wife anne kitson, and of john trelawney of menheniot, cornwall and his wife anne reskymer. his stepfather was sir robert gardiner, lord chief justice of ireland. he was educated at emmanuel college, cambridge, graduating in 1603, followed by middle temple until 1606. at university, spring became a close friend of another student from suffolk, john winthrop, with whom he would correspond for the rest of his life.