Harold Gillies, now considered to be the father of modern plastic surgery, developed most of his techniques (many of which are still in use today) specifically to reconstruct the faces of men who'd been injured in WW1.
Advances in weaponry meant that, for the first time, men were coming home from war with literally half their faces blown off, on a regular basis. This was not only traumatic— there were cases of men cancelling engagements or being afraid to see their families, because of their disfigurements— but also caused problems with every day tasks like speaking and eating, in which your face plays a pretty key role.
Gillies arranged for a whole ward, and later a hospital, to be dedicated to the treatment of these men, and took steps to ensure that all soldiers who received these kinds of injuries on the battlefield would be sent to him directly. He developed methods for applying skin grafts so that larger portions of the face could be repaired.
He continued his work treating wounded soldiers throughout WW1 and WW2, and when both wars were ended— just in case he hadn't done enough to establish himself as a full on hero— he was then approached by a medical student named Michael Dillon, a trans man, and was able to use the same techniques he'd developed to reconstruct the penises of wounded soldiers to give him a phalloplasty. The first one ever performed on a trans man. He even diagnosed the guy with a condition to explain the frequent operations, so as to avoid outing him.
Dillon later wrote a book about trans-ness, which inspired Roberta Cowell, who became the first British transwoman to get a vaginoplasty, also performed by Gillies.
In both cases, the techniques he developed were still being used in similar operations decades later. Gillies himself stated that he wanted no publicity for performing these operations, saying that "If it gives real happiness, that is the most that any surgeon or medicine can give.”
