Born and raised in the Toxteth area of Liverpool to Adolf's half-brother Alois Hitler Jr. and his Irish wife Bridget Dowling, he later relocated to Germany to work for his half-uncle before returning back to London and later emigrating to the United States, where he received American citizenship (in addition to his British citizenship) and ended up serving in the United States Navy against his half-uncle and Nazi Germany during World War II, changing his surname after the war.

[1] The family lived in a flat at 102 Upper Stanhope Street, which was later destroyed during the last German air raid of the Liverpool Blitz on 10 January 1942.

Unable to rejoin his family due to the outbreak of World War I, he abandoned them, leaving William to be brought up by his mother.

Suspecting a trap, William fled Nazi Germany and returned back to England He again tried to blackmail his uncle with threats.

After making a special request to President Franklin D. Roosevelt, William was eventually approved to join the United States Navy in 1944; he relocated to the Sunnyside neighborhood of Queens, New York.

William was drafted into the United States Navy during World War II as a pharmacist's mate (a designation later changed to hospital corpsman) until he was discharged in 1947.

They moved to Patchogue, New York, where William used his medical training to establish a business that analyzed blood samples for hospitals.

[9] In his 2001 book The Last of the Hitlers, journalist David Gardner speculated that the four brothers had made a verbal pact not to sire children.

[10] His third son, Howard Ronald Stuart-Houston, worked as a Special Agent with the Criminal Investigation Division of the Internal Revenue Service (IRS) and died in a car accident on September 14, 1989 while driving on Route 25, New York, near to Dietz Avenue, in a head-on collision, while en route to subpoena for a money laundering investigation.

Bainbridge adapted the story into a play as The Journal of Bridget Hitler with director Philip Saville,[13] which was broadcast as a Playhouse (BBC 2) in 1981.

[14] Grant Morrison and Steve Yeowell's 1989 comic book The New Adventures of Hitler is likewise based on the alleged Liverpool visit.

[15] Stuart-Houston was mentioned in the second episode of the 2015-16 season of the British panel show QI which was called Military Matters and aired on 23 October 2015.