Harriet Monsell was an Anglican saint and nun born in 1811 at Dromoland Castle. Following the death of her husband, Charles Monsell, in 1850, she became a central figure in the Oxford Movement by establishing the Community of St John Baptist in 1852. This Augustinian order, often referred to as the Clewer Sisters, focused on social service for marginalized women. Under her leadership as Mother Superior, the community grew significantly, expanding its reach to include various institutions across Great Britain, India, and the United States.