Mitsuyo Maeda, was one of five of the Kodokan's top groundwork (Ne - Waza) experts that judo's founder Kano Jigoro sent overseas to demonstrate and spread his art to the world. Maeda had trained first in sumo as a teenager, and after the interest generated by stories about the success of Kodokan Judo at contests between Kodokan Judo and jujutsu that were occurring at the time, he changed from sumo to Judo, becoming a student of Jigoro Kano. Maeda left Japan in 1904 and visited a number of countries giving "jiu-do" demonstrations and accepting challenges from wrestlers, boxers, savate fighters and various other martial artists before eventually arriving in Brazil on November 14, 1914.
Gastão Gracie was a business partner of the American Circus in Belém. In 1916, Italian Argentine circus Queirolo Brothers staged shows there and presented Mayeda. In 1917, Carlos Gracie, the eldest son of Gastão Gracie, watched a demonstration by Maeda at the Da Paz Theatre and decided to learn judo. Maeda accepted Carlos as a student and Carlos learned for a few years, eventually passing his knowledge on to his brothers.
At age fourteen, Hélio Gracie, the youngest of the brothers, moved in with his older brothers who lived and taught traditional Japanese jiu-jitsu in a house in Botafogo. Following a doctor's recommendations, Hélio would spend the next few years being limited to watching his brothers teach as he was naturally frail. Over time, Hélio Gracie gradually developed Gracie Jiu Jitsu as a softer, pragmatic adaptation from Judo, as he was unable to perform many Judo moves, that required to oppose the opponent strength directly. Through the years Helio Gracie developed a system that focused on ground fighting, as opposed to Judo which enphasizes throwing techniques. Years later Helio Gracie Challenged Judo's legend Masahiko Kimura. According to Kimura in his book "My Judo", He thought of Hélio Gracie to be a 6th dan judo at the time of his fight with him in 1951 (http://www.judoinfo.com/kimura4.htm). However, there is no Kodokan record of Hélio Gracie having any dan grade in judo, but it is not unusual for a foreign judoka's actual grade to be higher than that officially granted and recorded by the Kodokan, as Kodokan ranks are maintained independently and have much more strict requirements.
Although Brazilian jiu-jitsu is largely identified with the Gracie family, there is also another prominent lineage from Maeda via another Brazilian disciple, Luis França. This lineage had been represented particularly by Oswaldo Fadda. Fadda and his students were famous for influential use of footlocks and the lineage still survives through Fadda's links with today's teams such as Nova União and Grappling Fight Team.
Source: Wikipedia