As the Princess grew older, she began to take part in public life with her parents.
She made her first public speech in October 1940, when she was 14. In a live broadcast, she sent a message during the BBC's children's programme to all the children of Britain and the Commonwealth, particularly to those children who were being evacuated for safety reasons.
Listen to the broadcast on YouTube:
In early 1942 Princess Elizabeth was appointed Colonel-in-Chief of the Grenadier Guards, and on her sixteenth birthday she carried out her first public engagement, when she inspected the regiment.
In April 1943, Princess Elizabeth carried out her first solo public engagement, when she spent a day with a Grenadier Guards tank battalion in Southern Command.
From that time onwards, her official duties increased. She was particularly involved with organisations connected with young people. She was President of the Queen Elizabeth Hospital for Children in Hackney and the National Society for the Prevention of Cruelty to Children.
From March 1944 onwards, she also began to accompany the King and Queen on many of their tours within Britain.
Shortly after her eighteenth birthday in 1944, Princess Elizabeth was appointed a Counsellor of State during the King's absence on a tour of the Italian battlefields and, for the first time, carried out some of the duties of Head of State.
In August that year, with Queen Elizabeth, the Princess received an address from the House of Commons, and replied on behalf of the Throne.
In September 1944, the Princess carried out her first official tour of Scotland with her parents, including her first opening ceremony in October, when she opened the recently reconstructed Aberdeen Sailors' Home.
The Princess's first flight by air was in July 1945, when she accompanied the King and Queen on a two-day visit to Northern Ireland.
In early 1945 the Princess was made a Subaltern in the Auxiliary Territorial Service (ATS). By the end of the war she had reached the rank of Junior Commander, having completed her course at No. 1 Mechanical Training Centre of the ATS and passed out as a fully qualified driver.