Mitsuyo Maeda was one of the finest judoka that ever lived and helped spread the art outside of Japan. Known as Conde Koma (Count Combat), he is said to have fought in two thousand no-holds-barred fights and was so successful, many see him as the ‘toughest man who ever lived’. When he emigrated to Brazil, he taught his art to Carlos Gracie who along with his brother Helio, would go on to develop Brazilian jiu-jitsu by adapting what they had been taught by Maeda, who is also often referred to as the father of BJJ.
Sources:
wikipedia.orggraciebarra-pa.com