Where did Brazilian Jiu-Jitsu come from?

A Japanese fighter named Mitsuyo Maeda immigrated to Brazil in the early 1900s and befriended a local politician named Gastão Gracie. In exchange for help, Maeda taught Gastão's son Carlos. Carlos taught his younger brother Helio, who was too frail for the physical techniques, so Helio modified everything to work with leverage instead of strength. That adaptation became BJJ. The world noticed when Royce Gracie, a skinny guy in pajamas, submitted much larger fighters in early UFC events.