The Prince of Wales and Duchess of Cornwall are "absolutely delighted" by the announcement the Duchess of Cambridge has given birth to a daughter, Clarence House has said.

Kate's second child was delivered at 8.34am today, less than three hours after she was taken to the Lindo Wing of St Mary's Hospital in Paddington, London. Both mother and baby are "doing well".

The baby girl weighed 8lbs 3oz and is formally a princess, although her name has yet to be announced.

William was at his wife's side in the delivery room at the exclusive private maternity unit - as he was for the birth of his son Prince George.

The Prince of Wales - who said he wanted his second grandchild to be a girl - and the Duchess of Cornwall are "absolutely delighted" by the news, a Clarence House spokesman said.

William's uncle Earl Spencer also reacted with joy to the announcement, saying: "It's wonderful news - we are all thrilled for all four of them."

Other members of both families - the Windsors and the Middletons - have been informed including the Queen and Duke of Edinburgh, and Prince Harry who is on the other side of the world in Australia.

The Duchess of Cambridge's daughter is fourth in line to the throne, the Queen's fifth great-grandchild and a spare to the heir - and Prince George's sister.

The birth was proclaimed on Twitter, by the age-old tradition of a bulletin erected outside Buckingham Palace and by a Town Crier who entertained the crowds who had gathered outside St Mary's Hospital.

Kensington Palace said in a statement: "Her Royal Highness the Duchess of Cambridge was safely delivered of a daughter at 8.34am. The baby weighs 8lbs 3oz."

It added: "Her Royal Highness and her child are both doing well."

The birth of the princess was announced formally to the world when a bulletin, printed with the details of the delivery, was placed on an easel erected in the forecourt of Buckingham Palace.

The ornate gold easel was the same one used to proclaim to the nation George's birth in 2013.

The brief bulletin - on foolscap-sized paper set in a dark wooden frame - was put into place by two footman and it said the Duchess was "delivered" of a daughter and gave the time of birth.

It was signed by a senior medical team led by consultant obstetrician Guy Thorpe-Beeston, surgeon-gynaecologist to the household, who delivered the royal baby.

Alan Farthing, the Queen's surgeon gynaecologist, who was engaged to popular BBC presenter Jill Dando when she was shot and killed in April 1999, was also part of the team.

Dr Sunit Godambe, consultant neonatologist at Imperial College NHS Trust, and Professor Huw Thomas, physician to the Queen and head of the medical household completed the team.

Meanwhile, The Queen wore pink for a girl as she carried out official duties 250 miles away from her new great-grandchild.

The Duke of York joined his mother in Richmond, North Yorkshire, at a military parade to mark the amalgamation of the Queen's Royal Lancers and the 9th and the 12th Royal (Prince of Wales's). The new regiment will be called The Royal Lancers.

Soldiers marched through the town before entering the grounds of Richmond Castle for the takeover by the new commanding officer.

The Queen was wrapped against the spring chill in a soft wool coat and silk-wool dress by designer Karl Ludwig. A Palace official described the colour as "rose".

Her hat was by Angela Kelly and she wore a brooch of the Queen's Royal Lancers.

Well-wishers applauded and congratulated her on the birth of her fifth great-grandchild.

During the ceremony, attended by hundreds of veterans, serving soldiers and their families, Brigadier Andrew Hughes make a speech from the stage in the grounds of the Norman castle in the market town.

And when he briefly ad-libbed to offer congratulations to the Queen on the Royal birth, those present cheered and applauded.

Afterwards, he said: "I had a speech and I thought a short ad-lib wouldn't go amiss.

"I turned around to look at her and she had a great big smile."

The mayor of Richmond was presented to the Queen after the official ceremony in the Royal Marquee and he too offered his best wishes.

Clive World said: "What a lovely person she is. She said she was enjoying Richmond and 'thank you very much'."

Lisa Rickett, wife of Captain James Rickett who worked on organising the event, also met the Queen.

The 45-year-old teaching assistant who is mother to Alex, 13, and Theo, four, also congratulated her on the birth.

She said: "She just thanked me with a big smile. She had a big beam on her face."