The Martyrology of Donegal is a book that serves as a calendar of the saints of Ireland. It was compiled by John O'Donovan, an Irish historian and scholar, in the mid-19th century. The Martyrology lists the names of hundreds of Irish saints, along with the dates of their feast days and other important events in their lives. The book also includes historical and biographical information about many of the saints, as well as notes on their cults and...