Britain's Queen Elizabeth has formally welcomed the President to the UK.
Michael D Higgins and his wife Sabina were greeted by the British monarch and her husband Prince Philip in Windsor.
The Queen is currently hosting a private lunch for the Presidential party.
Earlier they met with Prince Charles and Camilla the Duchess of Cornwall at the Irish Embassy in London.
Crowds gathered on the streets in Windsor for the ceremonial welcome during which the President and the Queen travelled in a horse-drawn carriage procession.
These people say the State visit is a momentous occasion:
