Born in 1741 in Edinburgh, Scotland, William Brodie was the son of a prominent cabinetmaker and was likely considered quite a disappointment to his parents. From an early age, he was reportedly a gambler and a playboy who was off gambling even while his father lay dying. He had a knack for charming family and friends into forgiving his excesses. After his father died, Brodie apparently straightened out his life to become a successful cabinetmaker in his own right. Not only was he a member of the Edinburgh city council, he was also elected deacon (chairman) of the local trades guild. Socializing frequently, he was a well-known figure in Edinburgh society.
During the evening hours, things were very different however. His gambling had continued and, finding himself running short of money, he decided to supplement his income through crime. Brodie's legitimate work gave him the opportunity to take wax impressions of the main doors of the various houses that he would later burglarize. Teaming up with an English locksmith named George Smith, his criminal career was impressive (he and his gang once stole the silver mace from the University of Edinburgh).
The energetic Brodie certainly needed the income from his criminal activities. In addition to fueling his chronic gambling, he also maintained two mistresses in separate households (neither of whom knew about the other), and had numerous children. While his gang continued to terrorize Edinburgh, Brodie maintained his image as a prosperous businessman. As a respected cabinetmaker and carpenter, he was in a position to install locks and security devices in businesses and private homes across the city (while checking out places for his gang to rob).
It all came to an end with a disastrous armed raid on a government Excise office in Chessel's Court, Canongate in 1786. Although Brodie planned the operation himself, too many things went wrong and the gang only barely escaped. The city council posted a huge reward and one of the newer gang members (there being no honour among thieves) decided to turn King's evidence. Brodie managed to get word that the other gang members had been arrested and fled to Amsterdam. Things still grew too hot for him there and he was arrested by Dutch police just before he could board a boat to America.
Extradited back to Scotland, William Brodie went on trial on August 27th, 1788. The trial records are still available and make for fascinating reading. He pled not guilty and his testimony was filled with righteous indignation against the "designing villain John Brown" (the gang member who had turned him in). Building a case against Brodie would have been difficult if a careful search of his house hadn't turned up assorted burglary tools. William Brodie and George Smith were both sentenced to be hanged on October 1, 1788.
There still seems to be some confusion as to what happened with the actual hanging at the Tolbooth prison in Aberdeen. At least one account maintains that Brodie had arranged to wear a steel collar to the gallows (and had bribed the executioner to ignore it) so that he could survive the hanging. Despite the arrangements that he had made to have his body quickly removed, he could not be revived and was later buried in an unmarked grave in a churchyard in Buccleuch. There were later rumours that he cheated the hangman and fled to Paris but no real evidence exists of this.
It's not hard to see what inspired Stevenson to base his novel on William Brodie's double life. On one hand, he was a prosperous businessman and respected craftsman who, among other things, made much of the scaffolding on the gallows that was later used to hang him. On the other hand, he was the notorious leader of a gang of thieves that plagued Edinburgh for years. Much of the resemblance ends there though. Brodie was never a saintly Henry Jekyll, or even a thuggish Edward Hyde. He was just a full-time criminal who was particularly good at pretending to be law-abiding.
For all that there was no evidence of the psychological conflict that marked Stevenson's title character, the novel gave William Brodie a curious literary immortality. Along with a pub and alleyway named for him on Edinburgh's Royal Mile (which I plan to visit the next time I'm there), the novel is a strange monument to this once-feared master criminal.