So at one point or another, most people who practice BJJ wonder where it came from. I would first recommend doing a thorough google search to read the whole detailed history. But in a nutshell, here it is:
1532: First time "Jiu Jitsu" term was used (Japanese). Originally meant for the battlefield
~1870: Judo was developed from Jiu Jitsu by Jigoro Kano
1915: "Count Koma" introduces Jiu-Jitsu to the Gracie family in Brazil
1925: Carlos Gracie opens up his Jiu Jitsu school and with the help of his brothers (most notably Helio Gracie) develops BJJ into the sport/martial art as we know it today.
1993: The first UFC takes place, and Royce Gracie defeats all opponents by submission regardless of weight
Now a highlight of Royce back in the day