The Queen, the Duke of Edinburgh, the Princess Royal, Prince William and the Duke of Kent came to the South Bank's Royal Festival Hall on Wednesday afternoon for the Royal Society's convocation.
The Convocation of the Fellowship of the Royal Society is held once every 50 years.
This year the society is celebrating its 350th anniversary with See Further, a 10-day science festival at Southbank Centre.
As part of the convocation Prince William was admitted as a fellow of the society.
A specially commissioned fanfare by Julian Anderson was played by members of the London Philharmonic Orchestra as the royal party entered the Royal Festival Hall auditorium.