What's the Platinum Jubilee?

Context: The Platinum Jubilee of Elizabeth II was the international celebration in 2022 marking the 70th anniversary of the accession of Queen Elizabeth II on 6 February 1952. It was the first time that any monarch in British history celebrated a platinum jubilee, as is the case in the histories of the other Commonwealth realms.

Initiatives to commemorate the jubilee were announced by the governments of many realms—including Australia, Canada, New Zealand, Papua New Guinea, and the United Kingdom—of territories, such as the Cayman Islands and Gibraltar, and celebrations were also held in other Commonwealth member states, like the Gambia, Malaysia, Malta, Pakistan, and Samoa. Leaders from across the world, including from China, France, Germany, Israel, and the United States, sent messages of congratulations to the Queen on reaching the milestone. In the United Kingdom, there was an extra bank holiday on 3 June and the usual spring bank holiday was moved from the end of May to 2 June to create the four-day Platinum Jubilee Central Weekend from Thursday, 2 June, to Sunday, 5 June. Commemorative stamps and coins were issued by several Commonwealth nations and beacons were lit in every Commonwealth capital for the first time. In many places, trees were planted in the Queen's honour.

The Queen died in her Platinum Jubilee year, on 8 September, at the age of 96. Her funeral was held on 19 September 2022 and she was buried at the King George VI Memorial Chapel later that day.

Answer: The Platinum Jubilee was a 2022 celebration commemorating British Monarch Queen Elizabeth II's 70th anniversary on the throne. No other monarch in British history has lived long enough to celebrate this milestone, and celebrations were held in her honor all over the world, and several Commonwealth nations commemorated the occasion by issuing special stamps and coins.