The Duchess of Cambridge was a guest at the farewell gathering for Sir Marcus Setchell, the Queen’s surgeon-gynaecologist, at the Hyde Park Hilton.
Sir Marcus, 71, delivered William and Kate's baby, who is third in line to the throne, in July last year at the Lindo Wing of St Mary’s Hospital in Paddington, London.
Prince George was the third royal baby that the doctor had delivered, after the Countess of Wessex's two children Lady Louise Windsore and James, Viscount Severn.
The doctor was appointed Knight Commander of the Royal Victorian Order by the Queen shortly after safely delivering Kate's firstborn son.
This award is a personal gift from the monarch made independently of 10 Downing Street, given by the Queen to people who have served her, or her monarchy, in a personal way.
Since joining the Royal Household in 1990, Sir Marcus has served The Queen as Surgeon-Gynaecologist. As well as delivering the babies of the Countess of Wessex, he helped care for her after her ectopic pregnancy in 2001.
While he retired from the NHS in 2008, the doctor continued to practice privately and in a royal capacity, and was also on hand to look after Kate when she suffered from hyperemesis gravidarum at the beginning of her pregnancy.
The doctor’s farewell as he prepared to retire was also a fundraiser for the Wellbeing of Women, which works towards improving the health of women and babies across the UK.