Elizabeth Alexandra Mary Windsor was born at 02:40 (GMT) on 21 April 1926, during the reign of her paternal grandfather, King George V.

She was baptized by the Anglican Archbishop of York, Cosmo Gordon Lang, in the private chapel of Buckingham Palace on 29 May, and named Elizabeth after her mother.

The first official portrait of Elizabeth was taken by Marcus Adams in 1926.

Elizabeth's only sibling, Princess Margaret, was born in 1930. The two princesses were educated at home under the supervision of their mother and their governess, Marion Crawford.

Elizabeth met her future husband, Prince Philip of Greece and Denmark.

In September 1939, Britain entered the Second World War. Lord Hailsham suggested that Princesses Elizabeth and Margaret should be evacuated to Canada to avoid the frequent aerial bombing. This was rejected by their mother. The princesses stayed at Balmoral Castle, Scotland, until Christmas.

From February to May 1940, Elizabeth and Margaret lived at Royal Lodge, Windsor, until moving to Windsor Castle, where they lived for most of the next five years.

In 1940, the 14-year-old Elizabeth made her first radio broadcast during the BBC's Children's Hour, addressing other children who had been evacuated from the cities.

In 1943, Elizabeth undertook her first solo public appearance on a visit to the Grenadier Guards, of which she had been appointed colonel the previous year.

In February 1945, she was appointed as an honorary second subaltern in the Auxiliary Territorial Service with the service number of 230873.

The royal couple went on to officially confirm their engagement on July 9th, 1947, and hosted a photocall at Buckingham Palace, which allowed the future monarch to show off her new diamond ring.

Elizabeth and Philip were married on 20 November 1947 at Westminster Abbey.

Princess Elizabeth went in 1947 on her first overseas tour, accompanying her parents through southern Africa.

Elizabeth gave birth to her first child, Prince Charles, on 14 November 1948.

On 9 April 1952, Elizabeth issued a declaration that Windsor would continue to be the name of the royal house.

Queen Elizabeth II was crowned on June 2, 1953, in Westminster Abbey. 

Queen Elizabeth II attended ​with several of her prime ministers and other Commonwealth of Nations leaders at the 1960 Commonwealth Prime Ministers' Conference .

In 1978, the Queen endured a state visit to the United Kingdom by Romania's communist leader, Nicolae Ceaușescu, and his wife, Elena though privately she thought they had "blood on their hands".

Elizabeth II visited New Zealand with her husband Prince Philip in October 1981.

On 9 July, she awoke in her bedroom at Buckingham Palace to find an intruder, Michael Fagan, in the room with her. In a serious lapse of security, assistance only arrived after two calls to the Palace police switchboard.

In 1991, in the wake of coalition victory in the Gulf War, the Queen became the first British monarch to address a joint meeting of the United States Congress.

In March, Elizabeth's second son, Prince Andrew, and his wife, Sarah, separated.

In April, her daughter, Princess Anne, divorced Captain Mark Phillips.

In October 1994, the Queen became the first reigning British monarch to set foot on Russian soil. During the four-day visit, which is considered to be one of the most important foreign trips of the Queen's reign, she and Philip attended events in Moscow and St. Petersburg

A large fire broke out at Windsor Castle, Elizabeth's official residences, in November. Elizabeth came under increased criticism when angry demonstrators in Dresden threw eggs at her.

In a speech on 24 November 1992, to mark her Ruby Jubilee on the throne, Elizabeth called 1992 her annus horribilis (horrible year).

In November 1997, the Queen and her husband held a reception at Banqueting House to mark their golden wedding anniversary. She made a speech and praised Philip for his role as a consort, referring to him as "my strength and stay".

In 2003, the Queen had keyhole surgery on both knees.

In October 2006, Elizabeth missed the opening of the new Emirates Stadium because of a strained back muscle that had been troubling her since the summer.

On 20 March 2008, at the Church of Ireland St Patrick's Cathedral, Armagh, the Queen attended the first Maundy service held outside England and Wales.

Elizabeth addressed the UN General Assembly for a second time in 2010, again in her capacity as Queen of all Commonwealth realms and Head of the Commonwealth

Elizabeth made the first state visit to the Republic of Ireland by a British monarch in May 2011.

Elizabeth visited Birmingham in July 2012 as part of her Diamond Jubilee tour.

The Queen's 2012 Diamond Jubilee marked 60 years on the throne, and celebrations were held throughout her realms, the wider Commonwealth, and beyond.

On 3 March 2013, Elizabeth was admitted to King Edward VII's Hospital as a precaution after developing symptoms of gastroenteritis.

On 4 April 2013, she received an honorary BAFTA for her patronage of the film industry and was called "the most memorable Bond girl yet" at the award ceremony.

On 6 February 2017, Elizabeth became the first British monarch to commemorate a Sapphire Jubilee.

Elizabeth had cataract surgery in May 2018. the surgery took place at King Edward VII hospital.

In March 2019, she opted to give up driving on public roads, largely as a consequence of a car crash involving her husband two months beforehand.

On 19 March 2020, as the COVID-19 pandemic hit the United Kingdom, the Queen moved to Windsor Castle and sequestered there as a precaution. Public engagements were cancelled and Windsor Castle followed a strict sanitary protocol nicknamed "HMS Bubble".

Prince Philip died on 9 April 2021, after 73 years of marriage, making Elizabeth the first British monarch to reign as a widow or widower since Queen Victoria.