Complex sentence: Having gained a degree in Geography at Fitzwilliam College, Cambridge, he worked as a geography teacher at Bishop's Stortford College for six years in the late 1960s and 1970s, he then taught at Bedford School before returning to Bishop's Stortford College during the 1990s.
Split into simpler sentences: Having gained a degree in Geography at Fitzwilliam College, Cambridge, he worked as a geography teacher at Bishop's Stortford College for six years in the late 1960s and 1970s. He then taught at Bedford School before returning to Bishop's Stortford College during the 1990s.