 The Bears' rivalry with the Green Bay Packers is one of the oldest and most storied in American professional sports, dating back to 1921 (the Green Bay Packers were an independent team until they joined the NFL in 1921).In one infamous incident that year, Halas got the Packers expelled from the league in order to prevent their signing a particular player, and then graciously got them re-admitted after the Bears had closed the deal with that player.The franchise was an early success under Halas, capturing the NFL Championship in and remaining competitive throughout the decade.