In a speech to mark the 60th anniversary of her accession to the throne, she also paid a rare public tribute to the Duke of Edinburgh, her "constant strength and guide". Speaking in Westminster Hall, the oldest part of the Palace of Westminster, the Queen said the setting was a reminder of Britain's history and "national story".
To mark her Diamond Jubilee, MPs and peers have paid for a new stained-glasswindow for the 900-year-old hall, comprising her coat of arms.
"I have been privileged to witness some of that history and, with the support of my family, rededicate myself to the service of our great country and its people now and in the years to come." Her words were widely interpreted as a signal of the 85 year-old's determination to remain on the throne for the rest of her life.
As the Queen pointed out, she is only the second monarchto celebrate a Diamond Jubilee. Queen Victoria reigned for 63 years, the longest-serving monarch.
Members of the Royal family have said that the Duke's unwaveringsupport has been essential to the Queen's reign, but the couple themselves discuss their union only rarely. The Queen yesterday broke that habit with a warm joke about her husband's irasciblepublic persona.
The Queen's speeches to Parliament are usually written by the Government, but yesterday's address was personal, and included gentle jokes about the many politicians she had seen come and go.
"As today, it was my privilege to address you during my Silver and Golden Jubilees. Many of you were present 10 years ago and some of you will recall the occasion in 1977," she said.
Smiling, she added: "Since my accession, I have been a regular visitor to the Palace of Westminster and, at the last count, have had the pleasurable duty of treating with 12 prime ministers."
Laughter spread through the hall as her audience realised that her choice of the word "pleasurable" may not have been altogether serious.