The Detroit Lions are a professional American football team based in Detroit, Michigan. They compete in the National Football League (NFL) as a member of the National Football Conference (NFC) North Division. The franchise was founded in Portsmouth, Ohio, as the Portsmouth Spartans, and joined the NFL on July 12, 1930. Amid financial struggles, the franchise was relocated to Detroit in 1934 and renamed the Lions in reference to the city's Major League Baseball (MLB) franchise, the Detroit Tigers. The Lions have won four NFL championships (1935, 1952, 1953, and 1957). The team plays their home games at Ford Field in Downtown Detroit. The Lions have several division rivals, including the Chicago Bears and the Green Bay Packers, whom they have faced since 1930.