In 1922, the British Empire was at it's height. Britain ruled almost a quarter of the world and one-fifth of the world's population, a total of 33,700,000 square kilometers or 13,012,000 square miles of territory and 458 million people.
However, with any POD going back no further than 1840, make the British Empire by 1922 rule a majority of the earth's population by 1922. Bonus if it also rules the majority of the world's land mass.