R. Charleroi S.C. after their foundation, they qualified to play in the Promotion (then the second level in Belgian football) and in 1929, the club changed its name to Royal Charleroi Sporting Club. Rivals from Olympic Charleroi were playing in the first division in the late 1930s and the 1940s, while Sporting Charleroi was playing one level down, until they promoted in 1947. In 1949, Sporting Charleroi finished 4th (2 points behind Standard Liège) whereas Olympic Charleroi was 14th. But Olympic took the lead again until 1955 and their relegation to the second division. At the end of the 1956–57 season, Olympic Charleroi
Athletic Bilbao in European football opponent: Most-played opponent nationality: Athletic's selective signing policy, limiting themselves to players with a connection to the Basque region, has meant only one player who played international football for a country other than Spain has featured for the club in European ties: Fernando Amorebieta, who represented Venezuela. The club record for European appearances is currently held by Markel Susaeta on 75, having overtaken José Ángel Iribar's longstanding total of 55 in 2016. The highest goalscorer is Aritz Aduriz on 34, including 10 in the 2015–16 UEFA Europa League which won him the competition's "golden boot" award. Ernesto Valverde holds the