Complex sentence: Since then the club have had another 28 managers (excluding caretaker managers), the longest serving of whom was Bert Tann, who was in charge for eighteen years from 1950 to 1968.
Split into simpler sentences: Since then the club have had another 28 managers (excluding caretaker managers). The longest serving post-war manager was Bert Tann, who was in charge for eighteen years from 1950 to 1968.