The registrar who recorded the birth of Prince George is named Alison Cathcart and has been doing the job for 22 years.
She described today's duty as "a great pleasure" and said that it "cements an association with Westminster City Council and royal births in the borough that goes back decades"
"We registered the birth of the Queen and Prince Charles and Princes William and Harry so it's great to see that tradition continue," she added.
Cathcart has presided over several celebrity marriages including those of Sylvester Stallone, Joan Collins, Barbara Windsor and comedian David Walliams.
More top news
Colonel Richard Kemp told ITV News Britain must send in ground troops to have any chance of stopping the terror group.
Severe gales will gradually ease across the country but a wet night in the south of England and Wales and icy stretches in Scotland.
Two fathers' rights activists have avoided police and managed to climb on the roof of a public art gallery at Buckingham Palace.