*note

Toward the end of the 8th Century A.D., Ireland was almost completely Gaelic and Christian. It was a rural society, with no towns or cities, and the only large settlements were hamlets that grew up around monasteries. The monastery was, firstly, the seat of learning but was also involved in the cultural, economic and political affairs of its province.

On a crisp, calm morning in 795 A.D., a flotilla of longships slipped their moorings at a staging post, hidden deep within a cragged fjord in Norway. On board, were companies of well-armed, disciplined marauders, intent on conquering and plundering new lands. Many of those sailing that day were the younger sons of nobles and warriors who, because of a rapid rise in population and subsequent shortage of land, compounded by their low ranking within their families, were forced to seek fortune elsewhere. 

Expert boat-builders, they constructed the longship with precise attention to detail, speed being the main, determining factor. Ideally suited for open-sea voyages, it was lightweight, lay low in the water, had a wide beam, and was fast and stable. Fitted with oars as long as the boat itself and with cloth sails, woven from sheep’s wool, all ensured that they could increase speed when needed, and supplement the rowers' efforts.The design allowed navigation in shallow waters, making it ideal for river travel, and made beach landings much easier. With both bow and stern built identically, they could reverse direction without having to turn. Fully trained navigators sailed with the crews and used the sun, moon and stars as guides. The sun stone, shadow board and an early form of compass made certain that they reached their chosen destinations. 

On that fateful morning, sailing out from the fjord, they tacked southwest, skirted the Shetlands, and sailed south to Orkney. After a short respite there, they continued down the Atlantic Ocean, hugging the west coast of Scotland, entered the Irish Sea, and after bypassing the small isle of Manx, directed the convoy toward the land that lay furthest from the then-known civilization. Their target on this day was a small monastic settlement on Ireland's Lambay Island, which lay two miles off shore, close to Dubh linn, a marshy tide pool at the mouth of the River Liffey.

The settlement, built in 530 A.D., by an Irish scholar and monk named Colmcille, was home to a handful of monks and scribes. A church, monastery and several small, corbelled stone huts and simple shelters were built close to the site of the ancient stone-axe quarry. Rocks from the quarry were hewn by the monks, dressed by hand and utilized as the building material for the dwellings. Living a spartan existence, the monks possessed little and the only items of value were the books, religious artifacts and holy relics that adorned the church and monastery walls. 

The Norsemen, or as they are better known, the Vikings, had their own religion and worshiped a pantheon of Norse gods, some of whom promoted violence as a means to an end. They detested Christianity and saw it as a direct threat to their way of life and everything they held dear. That is one reason why they targeted monasteries and churches with such frequency, although they did also raid the houses of noblemen and isolated farms. Another attraction, and perhaps the deciding factor, was that the monasteries contained many gold and silver ornaments of worship.

They were also aware that the inhabitants of those settlements were god-fearing and peace-loving individuals, with only pitchforks and bill-hooks to defend themselves, no match for the heavily armed invaders. After looting the artifacts and relics, the settlement was destroyed in an unbridled orgy of destruction. The buildings were reduced to piles of smoldering rubble. The naked bodies of monks lay butchered, grotesquely strewn on the ground where they fell. Those not slaughtered were rounded up, shackled in readiness for transport back to the fjords, and their new lives as slaves.

That first raid was the beginning of 200 years of intermittent warfare and pillage, with monasteries the favored targets, but these raiders spared no one. The Vikings were expelled from Dublin in 902 A.D. but remained active in the Irish Sea. They continued to raid the Pictish kingdom in Scotland, the Saxon kingdom in Northumbria and frequently ravaged Manx. They returned to Ireland in 914, where they landed a large fleet of longships in Waterford. The Vikings were eventually defeated by King Brian Boru at the battle of Clontarf in 1014 A.D.

From "Out of the Ice: Ireland Then and Now."

Available at: https://www.amazon.com/author/johnabrennan

Read more here:

https://en.wikipedia.org/wiki/History_of_Ireland_(800–1169)