The origin of the strip’s premise is well-documented. The Dublin-born Bridget Dowling, former wife of Alois Hitler, had lived in Liverpool with her husband and their son, William. Alois would eventually abandon Bridget and William in England and immigrate to Germany, where his brother Adolf rose to political prominence. By 1939, William had begun a paid tour of America to talk about his now-infamous uncle, and Dowling accompanied him; around this time, she was inspired to write her memoir, My Brother-in-Law Adolf, in which she claimed that Adolf had lived with her, Alois, and William in Liverpool for about five months.

In 1912, Alois was an ambitious salesman of a new product — safety razors. According to Dowling, Alois had sent money to his sister Angela in Vienna so that she and her husband Leo Raubal could travel to Liverpool; Alois hoped to convince Leo to head up a central European office for the sale of safety razors. Alois and Bridget were surprised when Adolf (at this time, 23-years old) showed up instead; avoiding his required military service in Austria (using false documents identifying him as his deceased younger brother Edmund), Adolf had begged Angela to give him the money to travel to England and thereby elude the authorities.

Adolf’s arrival upset Alois; nevertheless, Alois and Bridget gave him lodging and clothing, with Adolf sleeping on their sofa most of the time. Bridget thought Adolf looked ill and impoverished, and found him unappreciative of their charity. He would sometimes play with William, then a two-year old, and sometimes pull out Alois’ collection of maps and lecture Bridget on his belief that Germany would one day dominate the world.

Bridget takes credit for introducing Adolf to astrology; she had an acquaintance named Mrs. Prentice who cast horoscopes, and Adolf frequently asked that Prentice cast his horoscope. She also takes credit for persuading Hitler to adopt his iconic trimmed mustache style. Although things were tense with Alois, the brothers did enjoy visiting London’s shipyards to admire the technology of Britain’s ships and bridges. Frustrated with Adolf’s extended stay, Alois eventually agreed to pay for Adolf’s travel to Munich, on the grounds that the city was culturally similar to Vienna and Adolf would not face extradition to Austria for avoiding his military service.

Dowling’s memoir was never finished, and it was never published in Dowling’s lifetime. Historians doubt the veracity of Dowling’s assertions, noting that early biographies of Hitler’s life observed that this period was a “lost year” in which nothing was known of Hitler’s activities in Vienna. Some argue that Dowling would have been aware of this “lost year” and that there was little risk in claiming Hitler visited Liverpool during this period in order to make money from potential book sales. The available historical documentation suggests that Hitler was in Vienna during the period of the alleged Liverpool visit.