sentences:  For example, he gave the date of St. Patrick’s death as 469, twenty-five years distant from the commonly assigned date of 493.In addition, the quality of his work is considered reliable enough to serve as a standard of comparison with other primary sources of the period, such as the Acts of St. Ailbe.Tírechán wrote in Latin, and historian Terry O’Hagan indicates that Tírechán’s work should be considered “a work in progress” in that he probably died before his work was complete.