United Kingdom

As of my last knowledge update in September 2021, Queen Elizabeth II was the reigning monarch of the United Kingdom. However, please note that my information might be outdated, and it's advisable to verify with current sources for the latest information. Here's some general information about Queen Elizabeth II up to that point:

**Name:** Queen Elizabeth II (Elizabeth Alexandra Mary Windsor)

**Born:** April 21, 1926, in London, England

**Reign:** Queen Elizabeth II became queen on February 6, 1952, following the death of her father, King George VI. She is the longest-reigning current monarch and the longest-reigning queen regnant in world history.

**Coronation:** Queen Elizabeth II's coronation took place on June 2, 1953, at Westminster Abbey in London.

**Family:** Queen Elizabeth II is the daughter of King George VI and Queen Elizabeth (the Queen Mother). She married Prince Philip, Duke of Edinburgh, on November 20, 1947. The couple had four children: Charles, Anne, Andrew, and Edward.

**Role:** As the constitutional monarch of the United Kingdom, Queen Elizabeth II's role is largely ceremonial. She serves as the head of state and performs various duties, including state visits, the State Opening of Parliament, and the granting of royal assent to legislation passed by Parliament.

**Commonwealth:** Queen Elizabeth II also served as the head of the Commonwealth of Nations, a voluntary association of 54 member states, until her passing. The Commonwealth includes countries that were formerly part of the British Empire.

**Important Events:** During her reign, Queen Elizabeth II witnessed significant events in the United Kingdom and the world, including the end of the British Empire's colonial era, the Troubles in Northern Ireland, various royal weddings, and changes in the political landscape.

Please note that this information is accurate up to September 2021, and there may have been developments or changes since then, including her eventual passing.