 Complete the following phrase:  Robson Gracie learned martial arts from his father, Carlos Gracie, and his uncle Helio Gracie. In the 1950s, Robson competed in Vale Tudo competitions. His début mixed martial arts fight was against Artur Emidio in April 1957. During the fight Gracie submitted his opponent, but refused to release him until the referee pulled them apart. Despite his small stature, incidents like this were to characterise Gracies professional life as a tenacious fighter. In the 1960s, Gracie served as a bodyguard to Leonel Brizola, the brother-in-law of the then President of Brazil, João Goulart. His political affiliations placed him under the scrutiny of the military regime, following the 