Theresa Yelverton (née Maria Theresa Longworth; – 13 September 1881) was an English writer who became notorious because of her involvement in the Yelverton case, a 19th-century Irish law case, which eventually resulted in a change to the law on mixed religion marriages in Ireland. Life to 1857 Maria Theresa Longworth was born in Cheetwood, Manchester, Lancashire, England, the youngest of six children born to Thomas Longworth, a silk manufacturer and his wife Ann Fox, who soon died. She was educated at Boulogne-sur-Mer in a convent of Ursuline nuns. A Roman Catholic convert, she subsequently returned to her father's house in Smedley, where they fell out over religion. She first met Major William Charles Yelverton, who from 1870 was 4th Viscount Avonmore, while aboard a steamer on the English Channel in August 1852. After this meeting, she completed her education, going to Italy. In Naples, she heard Yelverton was in Malta, and wrote to him asking for a favour; they began a correspondence. She returned to England, and nursed her dying father, and was there in 1854. Theresa Longworth was then a nurse for the Daughters of Charity of Saint Vincent de Paul (Sisters of Charity) during the Crimean War. She and Yelverton met again in 1855 at Galata Hospital in Constantinople. After the war was over, she visited the Crimea in March 1856, as the guest of Charles van Straubenzee and his wife. Yelverton saw her there socially. Marriages and court cases After some years of courtship with Theresa Longworth, Yelverton was posted to Edinburgh in early 1857. Theresa was staying there, with a friend who was another Catholic convert and a Sister of Charity, Arabella, daughter of Charles Macfarlane. Yelverton called on her, and their relationship, considered to be between engaged persons, became intimate. Theresa Longworth participated in two ceremonies of marriage with Yelverton. In the first, on 12 April 1857 the couple went through a ceremony of marriage at 1 Vincent Street, Edinburgh, Theresa's lodgings, according to the Book of Common Prayer of the Church of England, read out by Yelverton. In the second, she wed him secretly on 15 August 1857 in a Roman Catholic chapel near Rostrevor, County Down, Ireland. This was an exchange of vows before the altar at Killowen, witnessed by a priest, Bernard Mooney, who had previously consulted John Pius Leahy, coadjutor bishop of the Roman Catholic Diocese of Dromore. Yelverton later