Complex sentence: Smith took early retirement from the BBC, and in 1973 was appointed professor of liberal and contemporary studies at the New University of Ulster, a post he held until his retirement in 1979, when he was made professor emeritus.
Split into simpler sentences: Smith took early retirement from the BBC, and in 1973 was appointed professor of liberal and contemporary studies at the New University of Ulster. He held the post until his retirement in 1979, when he was made professor emeritus.