Horsemen are not born, they become. But how and why? Equestrian mastery requires a long and demanding apprenticeship from an early age. Yet the Greek civic cavalries depend heavily on the ability of cities to find, among their citizens, men to be custodians of an equestrian culture. Beyond the practice of horsemanship, we will highlight the different vectors of transmission of equestrian culture in Greek cities : family, environment, and the city itself through the ephebic institution.