Frank Richards succeeded Watson as club secretary in 1911, and when the First World War broke out he took over the managerial reins as well. Under Richards Birmingham won the Second Division title in 1921 and signed players such as Joe Bradford, Johnny Crosbie and Dan Tremelling who did much to keep the club in the top flight through the 1920s. He also forgot to enter them in the 1922 FA Cup. Billy Beer and Bill Harvey kept them in the First Division, albeit in the lower half of the table, before former Arsenal manager Leslie Knighton took charge in 1928. He led them to their first FA Cup final in 1931 and a top-half league finish the following year, but left when Chelsea made him an offer Birmingham were unable to match. Former Birmingham defender George Liddell kept them in the top tier until they were relegated in the last season completed before the Second World War, resigning in September 1939 when league football was suspended. His tenure of just over six years made him the club's longest-serving team manager.