A History of Llanallgo's
The Church of Saint Gallgo is one of the oldest Christian sites in Anglesey. Gallgo, the brother of Eugrad and of sister, Peithian, were three in large family. Gildas was another brother and is well known as the writer of De Excidio et Conquestu Britanniae, a very early British history. The family lived originally in the valley of the Clyde which was a part of Wales in the sixth century. Some members of the family arrived in Gwynedd as refugees fleeing the advance of the Picts who were invading what is now known as Scotland. Maelgwn, King of Gwynedd, granted the two brothers and their sister, land in a remote part of Anglesey where they established their llannau. Gildas was born in 500 and Maelgwn died in 547 so we can say that Gallgo, Eugrad and Peithian arrived in this remote part of Anglesey in the early part of the sixth century.
Gallgo, Eugrad and Peithian established their llannau within a mile of so of each other. Peithian’s llan was mid-way between those of Gallgo and Eugrad. We read ‘Both of them (Eugrad and Gallgo) alternately, each on his own day, used to celebrate with her the Daily Hours and the Mass, and taking food with her after Vespers, and returning thanks to God, they returned before sunset each to his own oratory … They were buried in the oratories which they had built, and are preserved there, famous and illustrious for their constant miracles’
Of these ancient oratories nothing remains. They would have been of simple construction of wattle and daub. The altars in these oratories would have marked the place of burial. St. Gallgo is celebrated on the 27 November. There is a reference to the Ecclesia de Nant, that is, the churches of Llanallgo and Llaneugrad in the Norwich Taxation of 1253 when the parish was taxed 17s9d!