The Treatise of St. Patrick’s Purgatory was adapted and translated across Europe, with the first female French poet, Marie de France, publishing a popular version around 1190.

St Patrick's Purgatory, a place of pilgrimage on Station Island in Lough Derg, County Donegal, circa 1935 (Getty Images) Read More: St. Patrick’s Day pilgrimage in Connemara - the trip of a lifetime ...