Queen Elizabeth marked her Diamond Jubilee on Monday with a message thanking all those who had supported her over her 60-year reign and reaffirming her dedication to serving the British people.

The 85-year-old monarch ascended the throne when her father, George VI, died on Feb. 6, 1952. She is the longest-serving monarch after Queen Victoria, who reigned for more than 63 years.

Before a year's worth of festivities to celebrate her milestone, the Queen said she and her husband have been "deeply moved" to receive so many kind messages about her Diamond Jubilee.

"I am writing to thank you for the wonderful support and encouragement that you have given to me and Prince Phillip over these years," she wrote in a message to the nation. "In this special year, as I dedicate myself anew to your service, I hope that we will all be reminded of the power of togetherness and the convening strength of family, friendship and good neighbourliness, examples of which I have been fortunate to see throughout my reign."

The Queen's Diamond Jubilee will be feted with a series of regional, national and international events throughout 2012.

Royals to tour Commonwealth countries

Over the course of 2012, members of the royal family — including Prince William and his wife, the Duchess of Cambridge — will fan out across the globe and travel to Commonwealth countries including Canada, Jamaica and Belize in honour of the queen's Diamond Jubilee.

The Queen and Philip, also known as the Duke of Edinburgh, will stay closer to home, touring the U.K. from March to July.

The 2012 Diamond Jubilee weekend will be held from June 2-5, with the main highlight likely to be a huge pageant on the Thames river featuring a 1,000-strong flotilla.

Elizabeth expressed hope that the coming year will be a time to give thanks "for the great advances" since she took the throne and "look forward to the future with a clear head and warm heart."

Later Monday, the Queen is slated to tour a nursery school and meet pupils there before watching a play about her 60 years as sovereign.