The Queen has wrapped up a week-long visit to Australia and Singapore, which saw her open the 2006 Commonwealth Games in Melbourne.
The Queen opened the 18th Commonwealth Games
She ended her tour with a day at a horse racing event named after her in Singapore.
The Queen left for Britain shortly after the race concluded.
Whilst overseas, the 79-year-old monarch also opened a new wing of Australia's Sydney Opera House, calling it "the symbol of a nation".
The Queen arrived in the Australian capital of Canberra last Sunday, where she was greeted by Prime Minister John Howard and Governor-General Michael Jeffery, along with a crowd of about 300 people.
On Monday she opened a new wing on the western side of the Sydney Opera House, which features large windows providing views of Sydney's harbour and skyline.
She officially opened the original building in October 1973.
On Wednesday the Queen arrived at the Melbourne Cricket Ground for what was the centrepiece of her tour - opening the 18th Commonwealth Games.
Around 80,000 spectators crammed into the stadium for a two-and-a-half hour ceremony.
However she was also met by protests when she arrived in the southern city.
Around 200 demonstrators calling for a treaty with Aboriginal Australians over land rights gathered outside a function the monarch was attending.
The monarch also faced a second demonstration on Friday when an Australian activist campaigning against cruelty to animals was detained by Singapore police.
Republican campaigners in Australia said the royal visit was an opportunity to reopen the debate about replacing the Queen with a home-grown president.
Allison Henry, national director of the Australian Republican Movement said: "Many Australians recognise that it is no longer sensible for us to have a citizen of another country, who visits Australia only occasionally, as our head of state."
A banquet was held in the Queen's honour in Singapore on Friday
But Mr Howard, told the BBC he did not believe Australia would become a republic "while the Queen is on the throne. Beyond that I don't know," he said.
Queen Elizabeth II last visited Australia in 2002 for the Commonwealth Heads of Government meeting in Queensland.
Royal aides have insisted that despite her age, this would not be the Queen's farewell tour of Australia.
After departing Australia, the The Queen and the Duke of Edinburgh arrived in Singapore.
While there she praised the common goals and close bonds between Britain and Singapore, at a banquet held in her honour.
She told dignitaries: "We are proud of our historical and Commonwealth links and as we look to the future we share a common vision of the societies we would like for our young people - safe, environmentally friendly and full of opportunity."
On her final day she attended the Queen Elizabeth II Cup, presenting the winning jockey and trainer with trophies.