Prince William and wife Kate left St. Mary's Hospital in London Tuesday with their first child, the third in the line of succession to the British throne.

The happy, smiling couple posed a few minutes for the press with His Royal Highness the Prince of Cambridge, who was born Monday.

A radiant Kate appeared carrying the baby wrapped in a white blanket.

After waving to photographers, the Duke and Duchess of Cambridge spoke to reporters in front of a microphone installed for the occasion.

"It's very emotional. It's such a special time. I think any parent will know what this feeling feels like," Kate said before handing the baby to her husband.

"He's got her looks, thankfully. He's got a good pair of lungs on him, that's for sure," William said. "He's a big boy. He's quite heavy."

Afterwards the couple went back in the hospital and minutes later William emerged carrying the baby in a car seat, which he put in the back with Kate and drove off to their residence at Kensington Palace.

Before leaving St. Mary's, where Prince William was born 31 years ago, the duke and duchess expressed their gratitude to the hospital staff "for the tremendous care the three of us have received."

The baby, whose name has not yet been announced, is the third in the line of successon to the throne, after his grandfather, Prince Charles, and his father, William.

The newborn is the third great-grandchild of Queen Elizabeth II, who has said she is "delighted" with the new addition to the family. EFE