Complex sentence: In 1975 he attended Staff College at Camberley, Surrey following which he was promoted major on 31 December 1975, and posted posting was as a Staff Officer, at HQ Northern Ireland from 1977 to 1979.
Split into simpler sentences: In 1975 he attended Staff College at Camberley, Surrey. Massey's next posting was as a major and Staff Officer, at HQ Northern Ireland from 1977 to 1979.