Dúnán was the first bishop of Dublin, appointed under Dublin's Hiberno-Norse kings. He is known also as Donatus or Donat. The diocese was put on a regular basis, in 1028, at the request of Sigtrygg Silkbeard

Sigtrygg Silkbeard

Sigtrygg II Silkbeard Olafsson was a Hiberno-Norse King of Dublin of the Uí Ímair dynasty...

. In his obit in the Annals of Ulster

Annals of Ulster

The Annals of Ulster are annals of medieval Ireland. The entries span the years between AD 431 to AD 1540. The entries up to AD 1489 were compiled in the late 15th century by the scribe Ruaidhrí Ó Luinín, under his patron Cathal Óg Mac Maghnusa on the island of Belle Isle on Lough Erne in the...

 Dúnán is described as "chief bishop of the foreigners" (ardespoc Gall).

It has been traditionally said that Dúnán was consecrated by Æthelnoth, the Archbishop of Canterbury

Archbishop of Canterbury

The Archbishop of Canterbury is the senior bishop and principal leader of the Church of England, the symbolic head of the worldwide Anglican Communion, and the diocesan bishop of the Diocese of Canterbury. In his role as head of the Anglican Communion, the archbishop leads the third largest group...

. This is now disputed, with scholars saying that his successor, Gilla Patráic

Gilla Pátraic

Gilla Patráic , also known as Patricius, was the second Bishop of Dublin. Gilla Patráic was elevated to the see of Dublin following bishop Dúnáns death in 1074, He was consecrated by Lanfranc, Archbishop of Canterbury...

, was the first to be consecrated in this way.