Complex sentence: There followed a nine-year period during which Grant held various secretarial posts in the administration, and during which, on 16 February 1835, he married Henrietta Isabella Phillippa Plowden at Calcutta Cathedral.
Split into simpler sentences: There followed a nine-year period during which Grant held various secretarial posts in the administration. On 16 February 1835, Grant married Henrietta Isabella Phillippa Plowden at Calcutta Cathedral.