Royals British Royal Family British Royal Family Deaths Queen Elizabeth Marks Historic 70 Years on the Throne in a Quiet Way The Queen became the longest-ruling monarch in U.K. history in September 2015 By Stephanie Petit Stephanie Petit Stephanie Petit is a Royals Editor, Writer and Reporter at PEOPLE. People Editorial Guidelines and Simon Perry Simon Perry Simon Perry is a writer and correspondent at PEOPLE. He has more than 25 years’ experience at PEOPLE covering the royals, human interest and celebrity. People Editorial Guidelines Published on February 6, 2022 09:00AM EST Sunday marks 70 years since the death of King George VI and the start of Queen Elizabeth's historic reign. The monarch, 95, quietly marked the occasion at her Sandringham estate in Norfolk, about 110 miles north of London. Known as Accession Day, the Queen normally spends the date in somber reflection at Sandringham, as it marks the death of her beloved father as much as the day that her life changed forever. In honor of the milestone, a new photograph of Queen Elizabeth was released that shows her with some of her official papers. Pictured earlier this week in the saloon at Sandringham House, where she usually likes to be for the anniversary as it is where her father passed away 70 years ago, she has with her one of her famous red despatch boxes. Prince Charles Praises Queen Elizabeth on Poignant Day, Is 'Deeply Conscious' of Her Wish for Queen Camilla Queen Elizabeth's portrait released on February 6, 2022 to mark the start of her Platinum Jubilee year. Chris Jackson/Buckingham Palace via Getty The box is one of thousands that contain documents needing her attention that she has received as Head of State over the last seven decades. The papers contain updates on matters of Parliament, the Commonwealth and events around the world, as well as State papers requiring the Queen's signature and Royal assent. She works on the papers most days of the year, apart from Christmas and Easter. For more on Queen Elizabeth celebrating her Platinum Jubilee, listen below to our daily podcast on PEOPLE Every Day. On Saturday, she announced that she would like her daughter-in-law Camilla, Duchess of Cornwall to be known as Queen Consort when the time comes for Prince Charles to take the throne. Dressed in a lime green summer wool tweed shift dress by Angela Kelly, her portrait outfit was decorated by two diamond ivy leaf clips, which were a gift from The Queen Mother for the then Princess Elizabeth's 21st birthday. Queen Elizabeth. Joe Giddens/POOL/AFP via Getty And poignantly, the photo beside her on the desk is of father King George VI at Buckingham Palace in 1948, four years before his death in 1952. The significant milestone this year marks what the palace calls the Queen's "70 years of service to the people of the United Kingdom, the Realms and the Commonwealth, and the beginning of the very first Platinum Jubilee year to be marked by a British Monarch." Royal Typo! Thousands of Souvenirs for the Queen's Platinum Jubilee Feature Embarrassing Misprint She is spending Sunday quietly and privately, possibly with some family members. Queen Elizabeth. Joe Giddens/POOL/AFP via Getty On Saturday, Queen Elizabeth opened up the Ballroom at Sandringham House to local charities and estate workers for a small reception, when she was said to be on "sparkling" form chatting to familiar faces and representatives of local organizations. The Queen typically stays at her estate in Norfolk starting in late December, when the royal family comes together to celebrate Christmas. However, the Queen decided to spend the holiday at Windsor Castle accompanied by Prince Charles and Camilla, Duchess of Cornwall amid the rise in COVID-19 cases in the U.K. A weekend of festivities to celebrate the Queen's Platinum Jubilee is planned for June. Beginning on June 2, events will include Trooping the Colour (the annual public festivities for the Queen's birthday), the lighting of Platinum Jubilee beacons, a service of Thanksgiving at St. Paul's Cathedral, the Derby at Epsom Downs, a live concert called "Platinum Party at the Palace," the Big Jubilee Lunch and the Platinum Jubilee Pageant. Queen Elizabeth and Prince Philip. getty Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more! Leading up to the weekend of events, members of the royal family will travel around the country to undertake a variety of engagements to mark the historic occasion. Queen Elizabeth became the longest-ruling monarch in U.K. history in September 2015, when she surpassed her great-great-grandmother Queen Victoria, who spent 63 years and 216 days on the throne. Queen Elizabeth. Hulton Archive/Getty Images; Oli Scarff - WPA Pool/Getty Images Queen Elizabeth has remained largely out of the public eye in recent months amid a series of health setbacks. She was seen walking with a cane for the first time since 2003 this past October. Shortly thereafter, it was reported she had been advised to give up horse riding and martinis, and she was hospitalized overnight on Oct. 20 for undisclosed "preliminary investigations." On Oct. 29, the Queen was advised to extend her rest period and only "to undertake light, desk-based duties." In late November, she held a number of in-person meetings and attended a joint christening for great-grandsons August Brooksbank and Lucas Tindall.