The Earl of Wessex has arrived at Frimley Park Hospital in Surrey to visit his wife Sophie, who last night gave birth to their first daughter in an emergency Caesarian operation.
Prince Edward rushed back from an official trip in Mauritius to be by his wife's side.
Watched by onlookers and the waiting media he smiled as he hurried through the hospital doors to see his wife.
Wearing a blue blazer, yellow shirt, tie and a poppy he was greeted by hospital staff and ushered into the building.
The baby, who is eighth in line to the throne and is the Queen's seventh grandchild, weighed 4lb 9oz and was several weeks premature.
Doctors at Frimley Park Hospital said both mother and daughter were "stable".
However, as a precaution, the baby was transferred to the neo-natal unit at St George's Hospital, Tooting, south London.
The Queen is said to be "delighted" by the news of her new grandchild.
Buckingham Palace said: "The Queen is being kept regularly informed on the progress of both mother and baby, and is pleased to hear that they are doing well."
A Palace spokeswoman added that any hospital visit by the Queen would be private.
Parents visit the Countess
The Countess's parents spent an hour-and-a-quarter with her on Sunday before going on to see the baby.
Mr Christopher Rhys-Jones said: "Sophie is absolutely fine. She's heavily sedated and rather sleepy but she is perfectly OK. The baby is also fine."
When asked if the baby had been given a name, he said: "It's really not my position to say.
The Countess, 38, who suffered a potentially life-threatening ectopic pregnancy two years ago, will stay in hospital "for the foreseeable future", the Palace said.
The Countess was admitted to hospital from her nearby home at Bagshot Park after she became unwell.
Until then, the pregnancy had been progressing well without complications and royal gynaecologist Marcus Setchell was due to deliver the child early in December.
It had been expected that the Countess would give birth at a private London hospital.
The baby, who will not be given the title of Her Royal Highness, will instead be known as Lady Windsor or possibly Mountbatten-Windsor.
Congratulation to couple