"[2] The letter is preserved in Bede's Historia ecclesiastica gentis Anglorum, but as it is recorded there it lacks any closing formulas, so dating it is difficult.
[3] Although a date of shortly after 610 has been put forward by Paul Grossjean, the letter could have been written at any time between around 605, when Laurence became archbishop and around 616, when King Æthelberht of Kent died and a pagan reaction against the missionaries set in.
Later scholars, including John Bale, attributed a letter entitled ad Brytannorum ecclesias, but this is mistaken.
[8] The Stowe Missal as well as the Martyrology of Tallaght, both of which were composed about 830, show that Dagán was revered as a saint at that point.
[9] The historian Roy Flechner has pointed out that it was possible that Dagán's refusal to share a meal or a roof with the Gregorian missionaries was a form of excommunication that is described in some Irish legal books.