[2] The Bonedd y Saint tells us that he was a son of King Sawyl Penuchel from the Old North or Yr Hen Ogledd; his mother was said to be Gwenaseth, daughter of Rhufon Rhufoniog.

During his exile (c. 545), Kentigern took himself to Wales and there founded the Celtic Monastery of Llanelwy (the church on the River Elwy), as the Welsh still call the city of St Asaph.

The 965 disciples, of whom Asaph was one, were divided into three groups: 300 of the unlettered farmed the outlying lands, 300 worked in the offices around the monastery, and 365 (the number corresponds to the days of the year) attended to the divine services.

[5] Although the traditional date of his death is recognised as 1 May, the current Roman Catholic liturgical calendar for Wales[6] keeps his memorial on 5 May, the 1st being designated for Saint Joseph the Worker.

[3] There are streets in Brockley, South East London; Christchurch, New Zealand; Bala Cynwyd, Pennsylvania; and in Alexandria, Virginia, and Leominster, Massachusetts named in his honor.