Clans of Ireland at the Battle of Clontarf

Battle Site - Clontarf Meadow, Dublin, Good Friday 1014

On the day of the Battle of Clontarf, Brian Boru, also known as Bryan Boru, gathered his troops outside the walls of Dublin near Kilmainham, to face his Leinster and Viking enemies. Some say these amounted to 20,000 loyal soldiers. From the records we can identify many of his supporters, and their descendants today can be very proud of their role in this legendary conflict!

Flanking Brian Boru were his five sons and grandson, and other O’Briens and Kennedys of the Dal gCais. In his central division were many of the clans of the Eóganachta, such as Molloy, ascendant of O’Mahony, O’Donoghues, Scanlans, O'Connells, O’Donovans and O’Carrolls.

The remaining Irish division came from the Connachta clans from the west and north west and included O’Kelly, O’Heyne or Hynes, O’Hartagan and other maritime tribes from the far west of Ireland and Scotland. 

The enemies faced each other at the site of the Battle of Clontarf, on the banks of the River Tolka, with the Danish ships filling the bay. By the end of the day, the casualties on both sides of this "spirited and furious battle" were enormous but the Leinstermen and his Viking allies were pushed into the river where many were drowned and soundly defeated.

The tribes of the south were victorious and had quashed any Danish hopes of overall dominion in Ireland. Brian Boru had validated his position as High King of Ireland and vanquished the foreigners for once and for all. Tragically, Brian Boru was slain in his tent, and his son Murrough and grandson and thousands more lost their lives.

This event immediately entered legend, with Brian Boru the epomymous hero and eternal hero of Irish independence. 

Irish Clans in the 11th Century

For centuries Celtic Ireland had been inhabited by a network of ruling tribes or clans who had their own territory and any number of sub clans who paid tributes to them in cattle and military support. This unusual structure meant that though there was a High King, his dominion did not always make subjects of the clans of Ireland. This struggle manifested itself in frequent raids and battles which have entered the legends and literature of Ireland of old. 

By the time the Vikings arrived in Ireland, the main tribes were the Dal gCais, the Uí Néillthe Eóganachta and the Connachta tribes. But the number of independent clans was increasing, territories were being subdivided and therefore weakening their collective strength in the face of new invaders. 

As the North of Ireland and Leinster, under the Uí Néill clans suffered most of the consequences of this intensifying struggle and either fought against or allied with the Danes, Munster, home of the Eóganachta and the Dal gCais, benefitted from this and grew stronger in power and men.

For the Dal gCais, the time to assert their claim for kingship had come. All they needed was a leader. He was Brian Boru.

The O'Brien Clan

The O'Brien Clan

The O’Briens had a large influence on the history of Thomond. Their dynasty is recognised as one of the oldest in the country and can be traced as far back as Milesius, one of the earliest kings in Ireland. This sept divided into several branches and their descendants of this name are the most numerous in the country. Today the O'Briens are Ireland's third largest clan with an estimated 750,000 so-named worldwide....read more

The Dal gCais Tribe and Their Clans

The Dal gCais Tribe and Their Clans

Dal gCais means 'peoples or children of Cas', who was a fifth century King of Munster and ancestor of the Dal gCais. They rose to power in the 10th century and produced a number of Kings including the legendary Brian Boru. In modern times they became known as the Dal gCais or Dalcassian Clan or Sept. A clan is usually a kinship group or group of families. A sept is normally seen as a group of clans and their families who are descended from the same ancestor, in this case, Brian Boru (Bryan Boru) and the O’Briens....read more

The Uí Néill Tribe and Their Clans

The Uí Néill Tribe and Their Clans

The O’Neill clan has one of the most historical and ancient lineages in Ireland if not the world. Their famous ancestor is Niall of the Nine Hostages, a legendary 4th century King of Ireland, who ruled from 377 to 404 AD, and is said to have conquered all of Ireland and Scotland and much of Britain and Wales. Because he took one royal hostage from each of the kingdoms he conquered he became known as such. He had twelve sons, four of whom settled in Ulster and began the dynasty there. Eoghan O'Neill gave his name to Tyrone. ...read more

The Eóganachta Tribe and Their Clans

The Eóganachta Tribe and Their Clans

The Eóghanachta Clan dominated southern Ireland from the 6th to 10th centuries from their seat in Cashel. In the 5th century this dynasty was founded by Conall Corc on and around the Rock of Cashel. The Eóganachta King Fíngen mac Áedo Duib ruled as King of Munster in the 7th century and is the direct male line ancestor of the O'Sullivans. His son Seachnasagh was too young to assume the throne and was therefore followed by Eóganachta King of Munster Faílbe Flann mac Áedo Duib, who is a direct male line ancestor of the later MacCarthy kings. This clan is remembered for their valiant defence of the Kerry region during the Viking Age....read more

High Kingship in Ireland

High Kingship in Ireland

Early and medieval Ireland was divided into many independent subkingdoms around which a hierarchy operated. This hierarchy rose from the rí tuaithe or king of a single petty kingdom, through the ruiri, a king who was overking of several petty kingdoms, to a rí ruirech, a king who was a provincial overking....read more

Heraldry in Ireland

Heraldry in Ireland

It is usually believed to have become widely used in the 12th century, when medieval weaponry was developing in Europe. Chain mail and long shields were replaced by full-body armour and helmets and smaller shields. In this way knights were unrecognisable so markings on their shields were vital. So they began to use two or three colours and gradually symbols were added. The Crusades were significant at the time (there were 8 between 1096 and 1271) and so Christian symbols like crosses and fleur-de-lys were common. Gradually the need for military recognition decreased and it became fashionable to denote something about the bearer’s territory, title or name. ...read more

Use of the Clan Coat of Arms in Ireland and Europe

A coat of arms is a unique heraldic design displayed on a shield or worn on a banner or garment by members of a clan or tribe in medieval Ireland. A Coat of Arms was used to protect, cover and identify the wearer, as advances in armour meant the wearer was often covered from head to foot! The design is a symbol unique to an individual person, and to his family.

In Ireland the use of banners dates back to Celtic times and they are mentioned in the several Annals written from the 11th and 12th centuries. It was anciently displayed in European countries on the front of a coat, thus is often called “Coat Armour”, where it became popular during the Crusades, and when the knight became the symbol of chivalry and protection.

In Ireland today since 1552, the use and the granting of the Coat of Arms has been regulated by the Irish Government, through the Office of the Chief Herald of Ireland. Today, coats of arms are still used by a variety of institutions including Universities and societies.For more information on Heraldry in Ireland and some common symbols used Click Here!