A mery chylde he was, so god me save
Wel coude he let blood, clyppe, and shave.
For centuries, surgery was a craft rather than a profession, and it was often practiced by barbers. In fact, up until the time of Sweeney Todd, a London resident would commonly visit a barber-surgeon for the treatment of a health problem. Besides providing grooming services, barber-surgeons regularly performed dental extractions, bloodletting, minor surgeries and sometimes amputations.
The association between barbers and surgeons goes back to the early Middle Ages when the practice of surgery and medicine was carried out by the clergy. But in 1215, a papal decree ruled that priests could no longer partake in any shedding of blood. Because barbers were accustomed to using a razor, it was presumed that they would be skillful in carrying out any treatment that involved cutting the skin, and so the practice was taught to them.
During the 14th and 15th centuries, the Black Plague wiped out a vast number of university-trained physicians, and barbers became increasingly relied upon for medical procedures. "Flying barbers" traveled from town to town, setting up tents and offering their services. In 1540, Henry VIII united the Company of the Barbers and the Fellowship of Surgeons with a royal decree and created one unified trade guild - the Company of Barber-Surgeons. Barbers and surgeons remained joined in this way for more than two centuries.
The practice of surgery was still in its primitive stage, but new discoveries were being made often. Barbers and surgeons regularly performed anatomical dissections on corpses to further their knowledge and master their craft. Though the guild ultimately divided, associating blood and dissection with the barber could have contributed to the lingering fear of barbers during this period.
In many versions of the Sweeney Todd story - including the 1973 Christopher Bond play - Sweeney Todd is identified as a barber-surgeon. In Bond's version, when Sweeney returns to London, he stages a public competition against another tradesman to see which of them could perform not only the best shave, but also the most deft tooth-extraction.