Sir Ernest Miles first performed his radical abdomino-perineal excision for carcinoma of the rectum in 1907. This event was the culmination of almost a decade of audit in which he carefully studied the outcomes of patients with rectal carcinoma. Miles's interpretation of his audit led, in a stepwise manner, to gradual changes in his operative technique and the eventual development of the radical abdomino-perineal operation; the operation that bears his name. The Miles operation and the principles upon which it is based, would lead to an improved outcome for patients with rectal carcinoma.