Constance Markievicz, the first woman elected to serve as an MP at Westminster, represented which party?

Although the American born Nancy Astor (1879-1964) was the first woman to take up her seat in the UK Parliament at Westminster, she was not the first woman to be elected to the house. That distinction goes to Constance Markievicz (1868-1927) who was elected as MP for the Dublin St. Patrick's constituency, and served in that role representing Sinn Fein, a party to this day linked to Irish nationalism, from 1918-1922. It should be explained that this was before partition, and all of the island of Ireland was under British rule.

Constance was the daughter of a wealthy Anglo-Irish family, and her father was a famed Arctic explorer. From an early age, living in the North of Ireland, she took a keen interest in the welfare of the local poor, and was also close friends with the poet William Butler Yeats who heavily influenced her politics.

Defying her family, she studied art, and whilst pursuing her studies in Paris, met her husband, the Polish Count, Casimir Markievicz.

Idealism turned to activism, and in 1916, she was sentenced to death for taking part in an armed rebellion, though this was commuted to life imprisonment and she was soon released. She was elected to parliament on both sides of the Irish Sea, but never took up her Westminster seat.

After her death (due to complications from appendicitis) she was not immediately recognised for her achievements, but this has now been rectified. To this day, Sinn Fein members don't take up their Westminster seats.