Probably the earliest biography, The Life of St Brigid, was written by Cogitosus, a monk of Kildare in the seventh century, and is a fine example of Irish scholarship in the mid-seventh century. A second First Life or Vita Prima of St Brigid is by an unknown author, although it is often attributed to St Broccán Clóen (d. 650). This book is occasionally argued to be the first written Life of St. Brigid, although most scholars reject this claim. The Life attributed to Coelan dating ca. 625, derives further significance from the fact that a foreword was later added to it by St Donatus, also an Irish monk, who became Bishop of Fiesole in 824. Donatus refers to earlier biographies by St Ultan and St Aileran. These differing biographies, giving conflicting accounts of her life, have much literary merit in themselves.