Lady Astor is elected as a Member of the Parliament of the United Kingdom. She is the first woman to sit in the House of Commons. (Countess Markievicz, the first to be elected, refused to sit.)

Nancy Witcher Astor, Viscountess Astor was an American-born British politician who was the first woman seated as a Member of Parliament (MP), serving from 1919 to 1945. Astor was born in Danville, Virginia, and raised in Greenwood, Virginia. Her first marriage, to socialite Robert Gould Shaw II, was unhappy and ended in divorce. She then moved to England and married American-born Englishman Waldorf Astor in 1906.

The Parliament of the United Kingdom of Great Britain and Northern Ireland is the supreme legislative body of the United Kingdom, and may also legislate for the Crown Dependencies and the British Overseas Territories. It meets at the Palace of Westminster in London. Parliament possesses legislative supremacy and thereby holds ultimate power over all other political bodies in the United Kingdom and the Overseas Territories. While Parliament is bicameral, it has three parts: the sovereign, the House of Lords, and the House of Commons. The three parts acting together to legislate may be described as the King-in-Parliament. The Crown normally acts on the advice of the prime minister, and the powers of the House of Lords are limited to only delaying legislation.

The House of Commons is the lower house of the Parliament of the United Kingdom. Like the upper house, the House of Lords, it meets in the Palace of Westminster in London, England. The House of Commons is an elected body consisting of 650 members known as members of Parliament (MPs), who are elected to represent constituencies by the first-past-the-post system and hold their seats until Parliament is dissolved.

Constance Georgine Markievicz, also known as Countess Markievicz and Madame Markievicz, was an Irish revolutionary nationalist politician, suffragist and socialist who was the first woman elected to the Parliament of the United Kingdom. She came from the upper class Anglo-Irish Protestant landowning elite of Ireland, which she abandoned in favour of Irish independence and social reform.