Professional boxing, or prizefighting, emerged in the early twentieth century as boxing gradually attained legitimacy and became a regulated, sanctioned sport. Professional boxing bouts are fought for a purse which is divided between the boxers as determined by contract. Most professional bouts are supervised by a regulatory authority to guarantee the fighters' safety. Most high-profile bouts obtain the endorsement of a sanctioning body, which awards championship belts, establishes rules, and assigns its own judges and referee.