She was the first child of The Duke and Duchess of York, who were later crowned King George VI and Queen Elizabeth.
At the time of her birth, Princess Elizabeth stood third in line of succession to the throne after Edward, Prince of Wales (later King Edward VIII), and her father, The Duke of York. But it was not expected that her father would become King, or that she would become Queen.
The Princess was christened Elizabeth Alexandra Mary in the private chapel at Buckingham Palace. She was named after her mother, while her two middle names are those of her paternal great-grandmother, Queen Alexandra, and paternal grandmother, Queen Mary.
She also spent time at the country homes of her paternal grandparents, King George V and Queen Mary, and her mother's parents, the Earl and Countess of Strathmore.
In 1930, Princess Elizabeth gained a sister, with the birth of Princess Margaret Rose. The family of four was very close.
When she was six years old, her parents took over Royal Lodge in Windsor Great Park as their own country home. In the grounds of Royal Lodge Princess Elizabeth had her own small house, Y Bwthyn Bach (the Little Cottage), which was given to her by the people of Wales in 1932.
Princess Elizabeth's quiet family life came to an end in 1936, when her grandfather, King George V, died.
His eldest son came to the throne as King Edward VIII, but, before the end of the year, King Edward VIII had decided to give up the throne in order to marry the woman he loved, Mrs Wallis Simpson.
Upon his abdication, Princess Elizabeth's father acceded to the throne as King George VI, and in 1937 the two Princesses attended their parents' coronation in Westminster Abbey.