London: Britain`s Queen Elizabeth II became a great-grandmother once again after her granddaughter Zara Phillips on Friday gave birth to a girl, the second royal baby to have arrived within months.
The baby, as yet unnamed, was born at Gloucestershire Royal Hospital and becomes 16th in line to Britain`s throne.
Zara Phillips is the daughter of Princess Anne, the Queen`s daughter, and is married to former England rugby player Mark Tindall.
Their 7 pounds, 12 ounces (3.5 kg) baby will be known as plain Miss Tindall without any royal title as she follows the female line of the monarchy.
She is the Queen`s fourth great-grandchild after Prince George was born to Prince William and Kate Middleton last July.
Mark Tindall expressed his joy on Twitter: "Thanks so much for all your kind messages. Definitely the best day of my life today, so happy! The girls are both doing great!"
The mother and baby have now left the hospital for Princess Anne, the Princess Royal`s Gatcombe Park estate in Gloucestershire.
"The Queen, The Duke of Edinburgh, The Princess Royal, Captain Mark Phillips and Mike`s parents, Mr Phillip and Mrs Linda Tindall, have been informed and are delighted with the news. The baby`s name will be confirmed in due course," the Queen`s press secretary said in a statement.
"The baby`s name will be confirmed in due course," the Secretary said.
Prime Minister David Cameron tweeted: "Many congratulations to Zara and Mike Tindall on the birth of their baby girl."
The new parents met during England`s Rugby World Cup-winning campaign in Australia in 2003.
Zara, 32, and Mike were married at Canongate Kirk in Edinburgh in July 2011.
Tindall is now a player-coach at Gloucester and?his wife has achieved sporting success in her own right as an equestrian.
As a member of the Great Britain eventing team, she won a silver medal at the London 2012 Olympics. She is planning to take part in the next Olympic Games, which will be held in Rio in 2016.