Charles Montgomery Burns was born Happy Burns to penniless parents in middle America. He lived from March 15,1886 until May 10,1995.
However,in one of the episodes from the 17th season (13th) Mr.Burns faces a question about his place of birth while helping Lisa;it is said that the answer he apparently gives is Tangier ( Morocco), but actually the answer he's really giving is "Pangea"; the supercontinent that is theorized to have existed during the Paleozoic and Mesozoic eras about 250 million years ago;Due to this error, in many other languages such as Spanish, French or Italian, the place of birth of Mr.Burns was mistranslated into Tangier instead of Pangea.
After being adopted by a faceless billionaire, he attended Yale University and eventually amassed his own personal enormous fortune. He is 104 years old (but in early years he said that he was 81). His mother, who had an affair with US President William Howard Taft, is still alive and is 123 years old (as of 1989) She died in 1993. In 1940, at a college reunion, he had an affair with a woman after seeing "Gone With The Wind" at a local movie theater. This affair produced an illegitimate son, Larry Burns, whom he knew nothing about until 1996.
He spent time as a biochemist and bioterrorist before purchasing the Springfield Nuclear Power Plant, where his fortune continued to grow. After accidentally killing his assistant, he secretly raised his son Waylon Smithers as his own. He is unaware that Smithers is gay and has had a crush on him for years. Their relationship has had its rough spots, as Smithers was one of the prime suspects in the shooting of Mr. Burns in 1995.
Since then, he has opened a casino, which failed, and has been a drug-runner between Canada and the United States. He is also the head of the local Republican Party, where he successfully persuaded Robert "Sideshow Bob" Terwilliger to run for Mayor of Springfield, and Krusty the Klown to run for Congress.
He currently lives at Burns Manor in Springfield, USA, and is known for his lack of emotion, amazing old age, and propensity for finding things "excellent". He penned an autobiography, entitled "Will There Ever Be A Rainbow?", in 1991.
In the episode "Flaming Moe", Mr. Burns full legal name is given as Charles Montgomery Plantagenet Schicklegruber Burns.