The origins of the College date to the fourteenth century with the foundation of the "Guild of Surgeons Within the City of London". Certain sources date this as occurring in 1368. There was ongoing dispute between the surgeons and barber surgeons until an agreement was signed between them in 1493, giving the fellowship of surgeons the power of incorporation. This union was formalised further in 1540 by Henry VIII between the Worshipful Company of Barbers (incorporated 1462) and the Guild of Surgeons to form the Company of Barber-Surgeons. In 1745 the surgeons broke away from the barbers to form the Company of Surgeons. In 1800 the Company was granted a Royal Charter to become the Royal College of Surgeons in London. A further charter in 1843 granted it the present title of the Royal College of Surgeons of England.
The correct way to address a member or fellow of The Royal College of Surgeons is to use the title Mr, Miss, Mrs, or Ms (not Dr). This system (which applies only to surgeons, not physicians) has its origins in the 16th century, when surgeons were barber-surgeons and did not have a medical degree (or indeed any formal qualification), unlike physicians, who held a University medical degree. When the College of Surgeons received its royal charter, the Royal College of Physicians insisted that candidates must have a medical degree first. Therefore, an aspiring surgeon had to study medicine first and received the title Doctor. Thereafter, having obtained the diploma of Fellow of the Royal College of Surgeons he would revert to the title "Mr" as a snub to the RCP. Nowadays the title "Mr" is used by Members of the College who have passed the diploma MRCS examination and the College addresses Members as "Mr" or "Ms".
"Come, come, we are not so far wrong after all," said Holmes. "And now, Dr. James Mortimer--"
"Mister, sir, Mister--a humble M.R.C.S."
Despite Mortimer's correction, he is referred to as "Dr. Mortimer" throughout the story.
A biographical register of fellows is available on Plarr's Lives of the Fellows Online