London - Former British prime minister Margaret Thatcher celebrated her 80th birthday at a party in London on Thursday with Queen Elizabeth II, current Prime Minister Tony Blair and a host of other eminent well-wishers.
A telephone call from US President George W Bush delayed the baroness's arrival at the hotel where her private bash took place.
But when she finally appeared, looking frail but happy, the so-called "Iron Lady" triggered a frenzy of paparazzi camera flashes.
She stood for a few moments, dressed in dark blue -- the colour of her once mighty Conservative Party -- before walking up a red carpet into the hotel, where some 650 guests were gathering to join in her birthday celebrations.
Admired or despised, Britain's only female prime minister changed the country dramatically during her 11-year premiership. She led her party to three consecutive election wins before quitting office in 1990.
In recent years, Thatcher has suffered a series of minor strokes and was told to stop public speaking in 2002 by her doctor on health grounds.
Guests at the party -- who included Thatcher's children, Mark and Carol, singer Shirley Bassey, actress Joan Collins, novelist Frederick Forsyth, and media tycoon Rupert Murdoch -- sang her praises.
"She is the Iron Lady and I want to be just like that when I grow up," joked Collins.
Dressed in a sparkling cream ensemble, the queen arrived for the celebration with her husband the Duke of Edinburgh at the rear entrance of the Mandarin Oriental Hotel in west London, where they were greeted by Thatcher.
Putting party differences aside, Blair, who leads the governing Labour Party, also attended the evening with his wife Cherie, while Conservative leader Michael Howard was there with his wife Sandra.
Howard saluted his predecessor.
"She has made an enormous contribution to the life of our country," he said.
"People forget what a state the country was in in 1979. We were on our knees, we were the sick man of Europe.
"The bulk of the credit for the turnaround that has taken place since then belongs to her."
The celebration started at about 7:00pm (18h00 GMT) and lasted for about three hours, about all Thatcher can manage nowadays without tiring out.
The baroness, without her late husband Sir Denis since 2003, also suffers from memory loss and always has aides close at hand.
Conservative member of parliament (MP) John Redwood, emerging from the party, said Thatcher made a short speech to her guests.
"It was a wonderful family occasion. There were a lot of people who loved what Margaret did and a lot of people who loved Margaret as a person," he said.
"She was in very good health, in very good form. She spoke extremely well and she spoke generously about all the people who had helped her doing what she did in the 1980s."
Thatcher began the day with a relaxing breakfast at her plush central London townhouse, though her presents were not being delivered there for security reasons.
She is due to meet former Soviet leader Mikhail Gorbachev and former US secretary of state Henry Kissinger next week as part of her birthday celebrations.
The Conservative Party has floundered since Thatcher's exit. It narrowly won a general election in 1992 under her successor John Major, but lost spectacularly to Blair's Labour Party in 1997 and the two subsequent general elections.
The party is now searching for its fifth leader since Thatcher.
Of the four men battling to replace the outgoing Howard, only right-wingers David Davis and Liam Fox were invited to the party.