 During World War I, Celtic won the league four times in a row, including 62 matches unbeaten between November 1915 and April 1917.The mid-1920s saw the emergence of Jimmy McGrory as one of the most prolific goalscorers in British football history.Over a sixteen-year playing career, he scored 550 goals in 547 games (including 16 goals for Clydebank during a season on loan in 1923–24), a British goal-scoring record to this day.