Football is the most popular sport in Scotland. Three of the big cities, Glasgow, Edinburgh and Dundee, have two or three big football teams, and most cities have at least one team. The two most famous teams in Scotland are known as the "Old Firm". These are Celtic and Rangers. These two Glasgow clubs have a lot of history, and are fierce rivals, often causing fights, riots and even murders between the fans. Rangers are world record holders, having won the most amount of league titles of any football team, currently 54.