This book was compiled towards the end of the 14th century at the castle of Ballymote for Tonnaltagh McDonagh, who was then in occupation of the castle. The chief compiler was Manus O'Duignan, one of a family who were ollavs and scribes to the McDonagh and the McDermots. Other scribes of the book were Solomon O'Droma, a member of a famous Co. Fermanagh family, and a Robert McSheedy. The book is a compilation of older works, mostly loose manuscripts and valuable documents handed down from antiquity that came into possession of McDonagh.