Japanese Jiu-Jitsu was one of the earliest martial arts to be formed into a system that could be practiced and taught. It came long before the Brazilian version, which wasn't formed until the early 1900s that a Brazilian family, the Gracies, took the ancient Japanese martial art and modernized it. Today their Brazilian version is taught in schools all over the world and is recognized as one of the most effective forms of self-defense.
The origins of Japanese Jiu-Jitsu are unclear because it formed centuries ago. It's even speculated to have originated in India among Buddhist monks who were looking for a way to peacefully defend themselves.
The name Jiu-Jitsu can be roughly translated as the "peaceful way" which means that it's meant to be performed without weapons.
Japanese Jiu-Jitsu, which was known as Judo at that point, was introduced to the Gracie family in Brazil in 1914 Esia Maeda, a Judo champion. One of the members of the Gracie family, a boy named Helio, was physically frail and unable to participate as a boy. Instead, he watched his brothers teach classes at their family's Jiu-Jitsu gym.
One day his older brother showed up to teach a class and Helio stepped in to teach for him. He taught well since he had been memorizing the techniques for years from the sidelines.