London - Britain's Queen Elizabeth II paid a visit Wednesday to Prince William and his wife Kate's newborn son, her great-grandson who is third in line to her throne.

William and Kate were spending their first day at home at Kensington Palace with the unnamed baby boy, after showing him off to the world's media outside their London hospital on Tuesday.

The 87-year-old monarch was seen arriving in a green Bentley after making the short trip from Buckingham Palace.

She had not visited the family in hospital and Wednesday's visit to Kensington Palace marked her first meeting with her new heir, who is her third great-grandchild.

The queen had told a guest at a Buckingham Palace reception on Tuesday that she was "thrilled" about the latest addition to the royal family.

She had joked last week that she was impatient for Kate to give birth because she was due to head off on holiday.

"I would very much like it to arrive. I'm going on holiday soon," she said.

The queen traditionally spends her summer holidays on her private Balmoral estate in Scotland.

The baby is third in line to inherit her throne, after her son Prince Charles and his son William.

There have not been three direct living heirs to the British throne since 1894.