It might be hard to believe, but in ancient times, Dublin was once a great naval power. In the year 870 AD, 200 ships set sail from Dublin to attack the fortress of the Britons on the River Clyde in Scotland.

In a previous blog post, we provide a brief history of Viking Dublin. By this time, the Norsemen were well established in Ireland and Dublin was a large Norse town and the most significant settlement in the Viking’s Western Sea.

Viking Dublin Was a Seafaring Town

The is little doubt that Viking Dublin was a center of shipbuilding. Excavations at Wood Quay in the 1970s revealed a wealth of artifacts associated with the craft. Although a complete Viking ship has never been discovered in Dublin, ship stems, keels and nailed ship’s planks as well as wood-working tools and ship models and drawings have been found.

Dublin-Built Viking Ship at The Viking Ship Museum in Roskilde, Denmark.

A great Viking longship built in Dublin is on display at the Danish Viking Ship Museum. Tree ring analysis shows that the boat was built in Dublin about 1042. According to the Museum, the ship is a masterpiece of naval engineering. The long, narrow shape of the ship and the enormous sail allowed at the ship to travel at great speed. And the manning of 60 oars made it possible to keep the ship moving even without wind.

So profound was the influence of Viking seafaring in Ireland that many seafaring words in Irish originate from Old Norse.

Some Irish Words of Old Norse Origin

Irish                            English                      Old Norse

ancaire                                anchor                                  akkeri

bád                                        boat                                       bátr

scod                                       sheet/sail                            skaut

stiúir                                      rudder                                  stýri

dorú (dorgha)                   fishing-line                          dorga

langa                                    ling (fish)                             langa

trosc                                      cod (fish)                             porskr

Who Were The Britons of Strathclyde?

The Ancient Britons were a Celtic tribe from Europe who settled in Britain during the Iron Age. They spoke a Brittonic language similar to modern Welsh and before the arrival of the Romans, controlled all of England and Wales. After the collapse of Roman power in Britain, the Britons came under increasing pressure from the other tribes in Britain. Gradually their area of control shrank and fragmented. The Welsh in Wales, the Cornish in Cornwall and the Britons in Scotland. The isolated Cumbric-speaking community in Scotland were referred to as the Hen Ogledd or Old North by their Welsh Brethren.

By the 9th Century, the Britons of the Clyde at their fortress of Dumbarton were in a precarious position. They were surrounded by hostile tribes; The Picts and the Gaels to the north and the Angles and Saxon tribes to the South. Of course, the arrival of The Vikings in 793, with the attack on the Abbey at Lindisfarne, was bad news for everyone. By the 870’s the Vikings we in full invasion-mode, with their Great Heathen Army destroying all before them in the lands of the Anglo-Saxons to the south.

The Fortress at Dumbarton

There is a city of the Britons. highly fortified to the present day that is called Alcluith

Bede’s Ecclesiastical History of The English People, 731 AD
Dumbarton Rock Stands Majestically on The River Clyde

The Britons called their fortress Alt Clud – the rock of the Clyde. From this imposing rock they ruled their kingdom, which stretched from Loch Lomond in the north to Ayreshire in the south. The strategic position of the stronghold also gave the Britons control over the river traffic on the Clyde.

The Siege of Dumbarton

It was in the year 870, Olaf The White, the Norse King of Dublin and his brother Ivarr – Amlaíb and Ímar in Gaelic – set sail from Dublin with a fleet of 200 ships. The armada sailed across the Irish Sea and up the Firth of Clyde to lay siege to the the fortress of Dumbarton.

Help From The Hebrides

Olaf’s wife, Aud, was the daughter of Ketill Flatnose who was King of the Isles. The isles comprised The Hebrides, The Isle of Man and the smaller islands of the Firth of Clyde. These islands were known to the Vikings as the southern isles, not to be confused with the northern isles of Orkney and Shetland. This familial relationship suggests that the Dublin forces may have been reinforced with ships from the isles.

Although the motivation for the attack can only be speculated, we can imagine the strategic advantage to the Vikings of the Isles in victory over the Britons of Strathclyde. Vikings being Vikings, the motivation was probably just plunder and profit.

Obsesio Ailech Cluathe e Nordmannuis, Amlaiph et Imhar ii regis Nordmannorum obsederunt arcem illam st destruxerunt in fine 4 menisum arcem et predaverunt.

The siege of Ailech Cluathe by the Northernmen, Olaf and Ivarr, two kings of the Northernmen besieged the citadel and at the end of four months destroyed and plundered it.

The Annals of Ulster

After a four-month siege, the well on the rock ran dry and the besieged Britons were doomed. The citadel was stormed by the Norsemen, the treasures plundered and the occupants carried off into slavery. The 200 ships sailed down the Clyde laden with treasure and slaves to be sold in the slave markets in Dublin.

What Became of The Defeated Britons

The Britons of The North must have reached an accommodation in defeat to the Vikings. The King Arthgal survived the siege to lead his people further up the Clyde to reestablish the Kingdom of Strathclyde at Govan, now a suburb of Glasgow.