He is from Hill Valley California. His best friend is his dog Einstein, and Marty McFly. Marty is a local high school student who helps Doc Brown out with his experiments.
Doc has been a scientist and inventor for many years. He first became interested in science as a child when he read the novels of Jules Verne. He has tried to invent many things, the majority of them were failures, including a machine to read people's thoughts. He has also had many successes, the grandest of which was the time machine he created using a DeLorean DMC-12. The time travel was only possible through Doc's invention of the Flux capacitor. It requires 1.21 Gigawatts of electricity, and makes time travel possible. He first came up with the Flux Capacitor after hitting his head on his bathroom sink on November 5th, 1955.
Doc had the dream of seeing the future, seeing mankind beyond his years. However, after going to the future, Doc states that his favorite time period was the "Old West." A time period in which he spent 8 months after getting struck by a bolt of lightning and getting stranded in 1880's Hill Valley. Doc failed to get back to 1985 with Marty, so he spent even more years there.
While there, he made a living as a Blacksmith, and would eventually fall in love and marry a school teacher, Clara. They would have two sons, Jules and Verne. He also made a second time machine out of a locomotive, which ran on steam, instead of the 1.21 gigawatts that the 1st time machine required. He then went back to 1985 to retrieve Einstein, and tell Marty that he was doing just fine. The last time that Doc is seen, Marty asks if he is going back to the future, and Doc replies "Nope. Already been there!" His locomotive time machine then lifts off and flies toward the screen just like in the first Back to the Future film.