Inter Milan was founded on Football Club Internazionale, following a schism from A.C. Milan.

Football Club Internazionale Milano, commonly referred to as Internazionale or simply Inter, and colloquially known as Inter Milan in English-speaking countries, is an Italian professional football club based in Milan, Lombardy. Inter is the only Italian team to have always participated in the top division of Italian football since its debut in 1909 and the only one that has never been relegated in Serie B. Since 1947, Inter has shared the San Siro stadium with AC Milan—the club from which it originally split. The San Siro is the largest stadium in Italy, with a capacity of 75,817. The long-standing rivalry between the two clubs, known as the Derby della Madonnina, is one of the most widely followed derbies in world football.

Associazione Calcio Milan, commonly referred to as Milan or AC Milan mainly outside of Italy, is an Italian professional football club based in Milan, Lombardy. Founded in 1899, the club competes in the Serie A, the top tier of Italian football. In its early history, Milan played its home games in different grounds around the city before moving to its current stadium, the San Siro, in 1926. The stadium, which was built by Milan's second chairman, Piero Pirelli, and has been shared with Inter Milan since 1947, is the largest in Italian football, with a total capacity of 75,817. The club has a long-standing rivalry with Inter, with whom they contest the Derby della Madonnina, one of the most followed derbies in football.

March 9 is the 68th day of the year in the Gregorian calendar; 297 days remain until the end of the year.