Prince Philip, Duke of Edinburgh (born Prince Philip of Greece and Denmark, Greek: Philippos Andreou, later Philip Mountbatten; 10 June 1921 9 April 2021), was the husband of Queen Elizabeth II. As such, he served as the consort of the British monarch from Elizabeth's accession as queen on 6 February 1952 until his death in 2021, making him the longest-serving royal consort in history.

Philip was born in Greece, into the Greek and Danish royal families; his family was exiled from the country when he was eighteen months old. After being educated in France, Germany, and the United Kingdom, he joined the Royal Navy in 1939, when he was 18 years old. In July 1939, he began corresponding with the 13-year-old Princess Elizabeth, the elder daughter and heir presumptive of King George VI. Philip had first met her in 1934. During the Second World War, he served with distinction in the British Mediterranean and Pacific fleets.

In the summer of 1946, the King granted Philip permission to marry Elizabeth. Before the official announcement of their engagement in July 1947, Philip relinquished his Greek and Danish royal titles and styles, became a naturalised British subject, and adopted his maternal grandparents' surname Mountbatten. He married Elizabeth on 20 November 1947. The day prior to their wedding, the King granted Philip the style His Royal Highness. On the day of their wedding, he was additionally created Duke of Edinburgh, Earl of Merioneth, and Baron Greenwich. Philip left active military service when Elizabeth ascended the throne in 1952, having reached the rank of commander. In 1957, he was created a British prince. Philip had four children with Elizabeth: Charles III; Anne, Princess Royal; Prince Andrew, Duke of York; and Prince Edward, Earl of Wessex and Forfar. In 1960, the Queen issued a British Order in Council, which declared that her and Philip's descendants who do not bear royal titles or styles may use the surname Mountbatten-Windsor, which has since also been used by titled members.

A sports enthusiast, Philip helped develop the equestrian event of carriage driving. He was a patron, president, or member of over 780 organisations, including the World Wide Fund for Nature, and served as chairman of The Duke of Edinburgh's Award, a youth awards program for people aged 14 to 24. Philip is the longest-lived male member of the British royal family. He retired from his royal duties on 2 August 2017, aged 96, having completed 22,219 solo engagements and 5,493 speeches from 1952. Philip died on 9 April 2021 at Windsor Castle, at the age of 99.

Elizabeth II (Elizabeth Alexandra Mary; born 21 April 1926) is Queen of the United Kingdom and 14 other Commonwealth realms.Elizabeth was born in Mayfair, London, as the first child of the Duke and Duchess of York (later King George VI and Queen Elizabeth). Her father acceded to the throne in 1936 upon the abdication of his brother, King Edward VIII, making Elizabeth the heir presumptive. She was educated privately at home and began to undertake public duties during the Second World War, serving in the Auxiliary Territorial Service. In November 1947, she married Philip Mountbatten, a former prince of Greece and Denmark, and their marriage lasted 73 years until Philip's death in 2021. They had four children: Charles, Prince of Wales; Anne, Princess Royal; Prince Andrew, Duke of York; and Prince Edward, Earl of Wessex.

When her father died in February 1952, Elizabeth—then 25 years old—became queen regnant of seven independent Commonwealth countries: the United Kingdom, Canada, Australia, New Zealand, South Africa, Pakistan, and Ceylon, as well as Head of the Commonwealth. Elizabeth has reigned as a constitutional monarch through major political changes such as the Troubles in Northern Ireland, devolution in the United Kingdom, the decolonisation of Africa, and the United Kingdom's accession to the European Communities and withdrawal from the European Union. The number of her realms has varied over time as territories have gained independence, and as some realms have become republics. Her many historic visits and meetings include a state visit to the Republic of Ireland in 2011 and visits to or from five popes.

Significant events have included the Queen's coronation in 1953 and the celebrations of her Silver, Golden, Diamond and Platinum jubilees in 1977, 2002, 2012 and 2022 respectively. Elizabeth is the longest-lived and longest-reigning British monarch, the longest-serving female head of state in history, the oldest living and longest-reigning current monarch, and the oldest and longest-serving incumbent head of state. Elizabeth has occasionally faced republican sentiment and press criticism of the royal family, particularly after the breakdown of her children's marriages, her annus horribilis in 1992, and the death in 1997 of her former daughter-in-law Diana, Princess of Wales. However, support for the monarchy in the United Kingdom has been and remains consistently high, as does her personal popularity.