The baby, third in line to the British throne, will be known as His Royal Highness Prince George of Cambridge.
The baby also got his first encounter with his great grandmother on Wednesday, as Britain’s Queen Elizabeth II visited him at Kensington Palace.
The royal couple left hospital on Tuesday and gave the world its first glimpse of the bundle of joy.
Emerging from St Mary’s Hospital with the baby prince to cheers from well-wishers. The Duchess said it was “a special time for any parent”.
After posing for pictures for the world’s media, the couple said they were still working on a name for their son and were feeling “very emotional”.