Complex sentence: Cornwell entered the junior seminary, Cotton College, in 1953 as a candidate for the priesthood, and proceeded to the senior seminary Oscott College, Sutton Coldfield, in 1958.
Split into simpler sentences: Cornwell entered the junior seminary, Cotton College, in 1953 intending to become a priest. He continued to the senior seminary Oscott College, Sutton Coldfield, in 1958.