A meeting with the Queen was so overwhelming for one little boy that he dropped to the floor and crawled out of the nearest door, shouting “bye” to amused onlookers.

Nine-year-old Nathan Grant was introduced to the Queen as part of her visit to Coram, the UK’s oldest children’s charity.

Based at the site of the Foundling Hospital in London, Coram has been helping vulnerable children since it gained a Royal Charter in 1739.

The Queen visited the charity on Wednesday to open The Queen Elizabeth II Centre, a national centre for children launched to mark the 350th anniversary of the birth of the founder, Thomas Coram.

The Queen was greeted on arrival by Edward Newton, 102, the oldest surviving pupil of the Foundling Hospital.

Newton mentioned to the Queen that he remembered King George’s visit to the hospital in 1926, saying: “I was a little tot”. A pupil at the school between the ages of six and 14, Newton left to join the army.

The author Dame Jacqueline Wilson and former Fame Academy judges David and Carrie Grant, who are Nathan’s parents, were among those attending. Wilson, who was one of the first Coram fellows, said: “I just think it’s a wonderful organisation and it’s very much to do with helping children now in new ways.”