Armagh

Armagh is the county town of the county Armagh in northern Ireland. It is of historical importance for both Celtic Paganism  and Christianity. 

Eamhain  Mhacha (or Navan Fort), at the western edge of Armagh, is believed to have been used as an ancient pagan ritual or ceremonial site. According to Irish mythology  it was once the capital  of Ulster. It was abandoned as such during the 1st century. The site was named after the goddess Macha, and as the settlement grew on the hills nearby, it was also named after the goddess — Ard Mhacha means "Macha's height". This name was later Anglicized as Ardmagh, which eventually became Armagh.

 According to tradition, when Christianity spread to Ireland during the mid-400s, Armagh became the island's "ecclesiastical capital". St Patrick established his principal community there. Saint Patrick was said to have decreed that only those educated in Armagh could spread the gospel. According to the Annals of the four Masters  in the year 457:
 
"Ard Mhacha was founded by Saint Patrick, it having been granted to him by Daire, son of Finnchadh, son of Eoghan, son of Niallan. Twelve men were appointed by him for building the town. He ordered them, in the first place, to erect an archbishop's city there, and a church for monks, for nuns, and for the other orders in general, for he perceived that it would be the head and chief of the churches of Ireland in general"

In 839 and 869, the monastery  in Armagh was raided by Vikings. As with similar raids, their goal was to acquire valuables such as silver, which could often be found in churches and monasteries.
The Book of Armagh came from the monastery. It is a 9th-century Irish manuscript now held by the Library of Trinity college (ms 52). It contains some of the oldest surviving specimens of old Irish.

graphics;  top left Navan fort  bottom right  St Patrick's Cathedral Armagh