Sir Harold Delf Gillies, born on June 17, 1882, in Dunedin, New Zealand, often stated the father of modern plastic surgery. His early life, marked by academic and sporting excellence at Gonville and Caius College, Cambridge, set the stage for a remarkable medical career. Following his initial foray into ENT specialization under Sir Milsom Rees, Gillies' path took a definitive turn during World War I. Joining the Royal Army Medical Corps, he witnessed nascent skin graft techniques by Valadier in France, which spurred his interest in reconstructive surgery. This led to a pivotal encounter with Hippolyte Morestin in Paris, deepening his fascination with facial surgery. Back in England, Gillies successfully advocated for a facial injury ward at Cambridge Military Hospital, Aldershot, later leading to the establishment of the Queen's Hospital in Sidcup in 1917. This institution, under Gillies' leadership, became a beacon of innovation in plastic surgery, performing over 11,000 operations on more than 5,000 men. Gillies' contributions extended beyond wartime. He developed a thriving private practice, collaborating with Rainsford Mowlem and mentoring his cousin, Archibald McIndoe. His influence continued through World War II, organizing plastic surgery units across Britain and training numerous Commonwealth doctors. A pioneer in sex reassignment surgery, Gillies performed groundbreaking procedures on Michael Dillon and Roberta Cowell, developing techniques that set standards for decades. His contributions to facial reconstructive surgery and gender affirmation surgery, encapsulated in his globally recognized books, have had a lasting impact on the field.