Share This Article

As night fell on the first millennium after the birth of Christ, an army of Irish kings sent nearly 7,000 Vikings to Valhalla. On Dec. 30, 999, at Gleann Mama (Glen of the Pass), a few miles west of Dublin, Malachy McDonnell, high king of Ireland, and rival Brian Boru, king of Munster, united to defeat the invaders. “The battle of Gleann Mama was great and rapid,” notes the 12th-century Irish chronicle Cogadh Gaedhel re Gallaibh (War of the Irish With the Foreigners). “No harder battle was ever fought.” New Year’s Day 1000 was the beginning of the end for the Norse in Ireland. “The evils they had hitherto inflicted,” the Cogadh records, “were now fully avenged on them.”

Dublin (from the Old Irish term Dubh Linn, or “Black Pool”), where the Rivers Liffey and Tolka and tributaries spill into the Irish Sea, was the first and last Viking stronghold in Ireland. Though the Norse threw open the city gates to the victors of Gleann Mama, according to the medieval Irish Annals of Clonmacnoise, the Irish “burnt the town, broke down the fort and banished Sigtrygg [II Olafsson], king of the Danes of Dublin, from thence.” Sigtrygg, known as Silkbeard, was half-Irish, but he chose the better part of valor and fled in his dragon ship.

Just as the Book of Revelation prophesies Armageddon (in present-day Israel) as the site of the battle to end all time, and Norse mythology foretells the end of the world during the cataclysmic events of Ragnarök, accounts left to us by first century scribes and bards describe Ireland as a battleground of gods. Their oft-conflicting tales cite heroes of both sides in Homeric terms. War horns blare, banshees keen, Norns weave the fates of men, and Valkyries select the slain. But just as Homer’s epic poem Iliad alludes to facts about forgotten Troy, the old tales hand down to us certain truths.

Brian Boru is a revered figure in Irish history, his image long used as a symbol of the indomitable spirit of the Irish people. In 1910 New York coin dealer Thomas Elder had a limited number of commemorative coins struck in both silver and aluminum to honor the Irish and Irish-Americans. (Image from Heritage Auctions, Dallas)

Over a period of 60 years Brian Boru, a son of the minor Dalcassian tribe, had risen to conquer the southern half of Ireland. Rather than contest him, Malachy of Meath made a pact with him against the foreigners. Leinster King Máel Mórda mac Murchada, on the other hand, sided with the Norse. After the slaughter at Gleann Mama in 999 Brian’s eldest son Murchadh dragged Máel Mórda from hiding in a yew tree, and as ruling only half of Ireland was not enough for a king of the Dalcassians, Brian soon forced Malachy off the high throne. The Cogadh, written a century afterward in part to justify the usurpation for Brian’s descendants, states that when he became high king, “peace throughout all Erin was made in his time.” He set Malachy, Máel Mórda and Sigtrygg back on their lesser thrones. To assuage their anger, he married his daughter Sláine to Sigtrygg and took for his queen their common curse, Gormflaith ingen Murchada, who was Máel Mórda’s sister, Sigtrygg’s mother and Malachy’s ex-wife.

The medieval Icelandic Njáls saga records her as Kormlada, “the fairest of all women, and best gifted in everything that was not in her own power, but it was the talk of men that she did all things ill over which she had any power.” Gormflaith bore Brian a son, but when Brian named Murchadh his heir, she stormed off to Sigtrygg in Dublin to plot revenge, “so grim was she against King Brian after their parting, that she would gladly have him dead.”

For a dozen years Gormflaith nursed her hate. Then one day she burned a fine coat Brian had given Máel Mórda, scorning her brother for having accepted it. The next morning, recounts the Cogadh, Máel Mórda happened on Murchadh playing chess with his cousin Conaing, king of Desmond, and scornfully advised the latter how to beat Murchadh. “Thou art he who gavest advice to the foreigners when they were defeated [at Gleann Mama]!” the perceptive Murchadh barked. “I will give them advice again,” Máel Mórda retorted, “and they shall not be defeated.” Murchadh advised him to find another yew tree in which to hide and then told his father of Máel Mórda’s deception. When Brian summoned his brother-in-law to answer for it, Máel Mórda killed the messenger. Continuing his rampage, Máel Mórda sent his warriors of Leinster against Meath, forcing proud Malachy to beg Brian’s protection.

Meanwhile, claims the Njáls saga, “Kormlada egged on her son Sigtrygg very much to kill King Brian, and she now sent him to Earl Sigurd to beg for help.” Sigurd Hlodvirsson the Stout ruled the Orkney Islands and northern Scotland under a banner bearing a raven, symbolic of Odin. Sewn by his mother, the banner had always brought him victory, though death to those who bore it. The earl agreed to support Sigtrygg on the condition Sigurd would be named “king in Ireland if they slew Brian.” He further demanded Gormflaith as his queen.

Gormflaith, accepting the terms and increasingly eager to avenge herself on Brian, next sent Sigtrygg to the Isle of Man, ruled by Danish brothers Ospak and Brodir, who boasted 30 dragon ships between them. “Find them,” Gormflaith advised her son, “and spare nothing to get them into thy quarrel, whatever price they ask.”

Kormlada [aka Gormflaith] egged on her son Sigtrygg very much to kill King Brian

“Brodir had been a Christian man,” notes the Njáls saga, “but he had thrown off his faith and become God’s dastard and now worshipped heathen fiends, and he was of all men most skilled in sorcery.” A deceitful Sigtrygg made him the same offer he’d made Sigurd, on condition the Danish mercenary keep it a secret. Brodir, said to wear his black hair so long he tucked it in his belt, accepted. His brother Ospak—also a heathen, but according to the Njáls, “the wisest of all men”—thought Brian a good king and opted to fight for him rather than against him. With his 10 ships he and his two sons broke through his brother’s blockade and sailed for Ireland to take baptism and swear fealty to Brian.

By Palm Sunday 1014 Vikings from England and Cornwall, the Orkneys, Shetlands and Hebrides, even the earls Plait and Anrad of Lochlann (Viking-held Scotland), arrived at Dublin to support Sigtrygg and Máel Mórda. Brian’s allied warriors of Munster, Connaught and Meath welcomed both Christian Norse and Gaels under Domhnall of Mar, in northeast Scotland. They laid waste around Dublin and camped on the plain of Clontarf (Cluain Tarbh, “Field of the Bull,” likely a reference to the city’s cattle pasture), which lay across the bay. The Norse would have to cross the Rivers Liffey and Tolka to reach them.

Brodir, according to the Njáls saga, employed sorcery to divine the outcome of battle: “If the fight were on Good Friday [April 23], King Brian would fall but win the day; but if they fought before, they would all fall who were against him. Then Brodir said that they must not fight before the Friday.

“On the fifth day of the week [Holy Thursday] a man rode up to Kormlada and her company,” continues the Njáls saga, “and in his hand he held a halberd.” The chronicler implies it was Odin himself, come to scheme with his kings. More likely the rider was a courier from Malachy to ex-wife Gormflaith, bearing an offer to betray Brian the usurper. “If [Malachy] would not attack the [Norse] foreigners,” the Cogadh contends, “the foreigners would not attack him. And so it was done, for the evil understanding was between them.”

On the eve of battle the Norse offered to abandon Dublin. The Irish watched them board their dragon ships, set sail and depart for home. But Brian must have suspected a trick, for it was said Aibhell, banshee of the royal house of Munster, visited him in his tent that night, portending his death.

Vikings from England and Cornwall, the Orkneys, Shetlands and Hebrides, and even from Scotland arrived to reinforce their comrades in Dublin. (Classic Image/Alamy Stock Photo)

As the sun rose on Good Friday, the dragon ships reappeared, riding the high tide to land unopposed on the north shore of Dublin Bay and disembark 2,000 warriors. Some 5,000 of Sigtrygg’s host sallied across the Liffey and Tolka to join them on the plain at Clontarf. (Some historians have placed the battle between the rivers, the Danes landing on the point where they meet, but consensus holds it was fought north of the Tolka.) Brian’s Irish numbered perhaps 5,000, not including Malachy’s 3,000 men of Meath. Other estimates claim as many as 20,000 troops on each side, making Clontarf an epic battle indeed.

The Vikings wore knee-length mail hauberks—Brodir a coat “on which no steel would bite”—and their weapon of choice was the two-handed battle-ax. Irish warriors disdained armor as unmanly and favored the javelin, said to make a bansheelike wail as it flew. The Dalcassians alone were famed for their one-handed Lochlann ax.

The lines squared off for combat, one flank on the bay, the other in Thor’s Wood, an oak grove sacred to the Norse. Both sides regarded strategy, tactics and cavalry as child’s play; this would be a contest of champions, fought toe to toe, man to man. The Vikings likely assembled behind a wall of shields in their customary wedge formation—the svinfylking, or “boar snout,” attributed to Odin himself. “Brodir was on one wing of the battle,” the Njáls saga relates, “King Sigtrygg on the other. Earl Sigurd was in the mid battle” with retainers Thorstein, Asmund the White and Hrafn the Red. Irish scribes sneer that Sigtrygg watched with Sláine from the battlements of Dublin, while Máel Mórda and his Leinster rebels stood to the rear.

The Cogadh notes Malachy and his warriors of Meath honored their treacherous bargain, refusing to take the field. Viking writers have the remaining Irish arrayed in three ranks. Ospak, his two sons with him, led one flank; Brian’s brother Ulf Hreda the Quarrelsome led the other; and the Desmonders under Conaing joined Murchadh’s Dalcassians in the center.

Regarded as Ireland’s greatest warrior, Murchadh fought with a sword in each hand, his son Turlogh and warrior-saint friend Dunlang O’Hartigan at his side. Seemingly alone among the Irish, Dunlang wore a cloak beneath which he could not be seen (likely a mail hauberk), said to have been a gift from the banshee Aibhell, who foretold all their deaths that day. “This is not good encouragement to fight,” Murchadh told Dunlang, “and if we had such news, we would not have told it to thee.”

King Brian’s son Murchadh led his father’s forces into battle against the Viking host. Neither Brian nor Murchadh survived the battle. The ultimate victors at Clontarf were those who had declined to fight. (C.F. Sargent/National Library of Ireland, PD B14)

Brian rode before his army beneath the Gal Gréine, the sunburst banner of Ireland’s high kings, a crucifix held high to remind all of another Friday a thousand years past. The elderly king, who was pushing 75, would not fight on a holy day and instead retired to his tent behind the Irish lines to pray, while his son led out the army. Some annals accuse Murchadh of riding too far in advance of the Irish ranks, perhaps at the point of a Vikinglike wedge. Domhnall of Mar urged him back in line, but the Irish prince would not show hesitation before his men.

Domhnall soon demonstrated his own courage. According to the Cogadh, Viking champion Plait of Lochlann proclaimed no man of Erin could stand against him. Domhnall was not Irish but accepted the challenge nonetheless. Plait then stepped forward.

“Where is Domhnall?” he bellowed.

“Here, thou reptile,” answered Domhnall, and the Scotsmen fought in single combat, the result proving fatal to both, who died with “the hair of each in the fist of the other, and the sword of each through the heart of the other.”

At that, the Cogadh records, the two hosts “began to hew and cleave, and stab, and cut, to slaughter, to mutilate each other.” In the center the Desmonders and Dalcassians followed hard-charging Murchadh, “for his was the fierce rushing of a bull and the scorching path of a royal champion…and he made a hero’s breach and a soldier’s field through the battalion of the Denmarkians.”

The north flank was a battle of Irishmen, pitting Liffey Prince Dunlang and 1,000 rebel Leinstermen against a like number of Connaught warriors. “These parties were equally matched,” the Cogadh notes, “[and] very nearly killed each other altogether.” The surviving Connaught warriors pursued the remaining Leinstermen into Thor’s Wood, caught Dunlang and beheaded him.

Ospak was badly wounded, and both his sons were killed. Brodir hacked his way through the Irish, his impenetrable armor shrugging off all blows, until he came up against Ulf the Quarrelsome, who indeed did not pierce his mail, but knocked him down once, twice, thrice. Brodir fled into Thor’s Wood.

In the center Conaing cut his way through to Máel Mórda, and the two former chess partners slew each other on the spot. Dunlang O’Hartigan singled out a Danish champion, ran a spear through him and took his head before the Vikings swarmed him. According to Irish legend, Murchadh heard him shouting above the din but couldn’t single out his cloaked countryman. “That voice is the voice, and these are surely the blows, of Dunlang O’Hartigan!” he chided. Shamed, Dunlang threw off his armor and was promptly struck down at Murchadh’s feet.

Malachy of Meath, watching from the sidelines, later recalled, “I never saw a battle like it, nor have I heard of its equal; and even if an angel of God attempted its description, I doubt if he could give it.” According to the Cogadh, Malachy and his bystanders were flecked with blood carried on the wind blowing across the battleground.

Sigtrygg, looking on from the walls of Dublin, is said to have remarked, “Well do the foreigners reap the field.” Sláine replied only that the outcome was far from decided.

In his tent Brian paused from his prayers to ask his attendant, Latean, whether Murchadh’s banner remained standing. Latean glanced outside. “It is standing,” he replied, “and many of the banners of the Dalcassians are around it, and many heads are falling around it.”

According to the Cogadh, Malachy and his bystanders were flecked with blood carried on the wind blowing across the battleground

The Battle of Clontarf reportedly lasted all day, the turning point coming near sundown. As it plowed relentlessly forward, the svinfylking was vulnerable to flanking attacks and missile weapons. Closing in on both sides, the javelin-wielding Irish would have caught the Norse wedge in a double envelopment, eventually cutting away the Viking shield wall. “That was the decisive defeat that took place on the plain,” the Cogadh claims, “for they were [almost] all killed.”

Latean told Brian the moment Murchadh’s flag passed through the enemy ranks. “The men of Erin shall be well while that standard remains standing,” the relieved king replied, “because their courage and valor shall remain in them all, as long as they can see that standard.”

The surviving Norse fled for their dragon ships. On the walls of Dublin it was Sláine’s turn to taunt Sigtrygg. “I wonder, are they in heat like cattle?” Brian’s daughter asked in jest. “If so, they tarry not to be milked.” A furious Sigtrygg hit her in the mouth, knocking out a tooth.

Meanwhile, the sea rovers found their earlier ruse had backfired. The fighting had gone on so long, the tide had gone out, come in and gone out again, floating their ships off the beach. Unable to swim in their armor, the Cogadh records, “the foreigners were drowned in great numbers in the sea, and they lay in heaps and in hundreds.”

On the field Murchadh, a sword in each hand, cornered Earl Sigurd under his raven standard and, true to the prophecy, first slew its bearer. Then, in one of the most dramatic passages of the Njáls saga, Sigurd called on his bodyguard Thorstein to take up the flag, but Asmund the White warned, “Don’t bear the banner, for all they who bear it get their death!”

“Hrafn the Red!” called Sigurd. “Bear thou the banner.”

“Bear thine own devil thyself,” Hrafn shot back.

“’Tis fittest that the beggar should bear the bag,” Sigurd said in resignation, tucking the banner into his hauberk. A moment later Murchadh dealt him a right-handed blow that knocked off his helmet, followed by a left-handed cut deep into his neck. Sigurd fell dead, and Asmund after him. Hrafn the Red fled into the river and was being dragged down when he saved himself with a hasty Christian prayer. Thorstein relied on the Irish sense of humor to save him. As the horde rushed him, he knelt to lace up a shoe. A bemused Irishman asked why he hadn’t fled like the others. “Because I can’t get home tonight,” Thorstein quipped, “for my home is out in Iceland.” The Irish gave him quarter.

The last 100 Connaughters caught the last 20 Danes trying to escape over the Liffey. Murchadh’s son Turlough was last seen chasing several Norse into the water near a stone weir. Their drowned bodies were found together, Turlough’s fingers knotted in the Norsemen’s hair.

Some annals claim at that point—with the Norse clearly losing—Malachy and his idle warriors of Meath entered battle to finish off the rebels of Leinster, routing them “by dint of battling, bravery and striking, from the Tolka to Dublin.” The Dalcassians say it never happened.

In the final moments of battle Murchadh laid into Anrad of Lochlann, but suffered a wound that “cleft his hand.” The warriors grappled to the ground. Murchadh managed to wrestle Anrad’s mail over his head, take the Viking’s own sword and run him through, but in his death throes Anrad drew his own knife and gutted the prince.

“Murchadh’s standard has fallen,” Latean reported to Brian.

“That is sad news,” said the king. “On my word, the honor and valor of Erin fell when that standard fell.” He then gave orders to be carried out on his seemingly imminent death.

Latean interrupted. “There are people coming toward us…a blue, stark naked people.”

“The foreigners of the armor,” said Brian, taking up his sword.

Having evaded the king’s guard, Brodir prepares to deliver the ax blow that ended both the life and reign of Brian Boru. (Private Collection/@Look and Learn/Bridgeman Images)

It was in fact Brodir, who had been skulking in Thor’s Wood. “Brodir saw that King Brian’s men were chasing the fleers,” the Njáls saga relates, “and that there were few men by the [king’s] shield wall. Then he rushed out of the wood, broke through the shield wall and hewed at the king.”

According to the Cogadh, even as Brodir raised his ax, Brian hacked off the Viking’s left leg at the knee, but “the foreigner dealt Brian a stroke that cleft his head utterly.”

“Now let man tell man that Brodir felled Brian,” the haughty Norseman told his men. It was his last order. The Njáls saga records that Ulf the Quarrelsome took Brodir alive, opened his belly, nailed his entrails to a tree and marched him around it, “and he did not die before they were all drawn out of him.”

The Irish had lost 4,000 killed; the Danes, 6,600. The ultimate victors of Clontarf were those who had declined to fight. Malachy reclaimed Brian’s high kingship and the next year subdued Dublin for good; Sigtrygg Silkbeard found Christ and retained his throne till death; Gormflaith saw her son by Brian crowned king of Munster. It may seem odd to us to regard Clontarf as Brian’s victory, but to the ancients death in battle was not defeat. “Brian fell, but kept his kingdom,” the Njáls saga affirms, “ere he lost one drop of blood.” In the millennium since, Brian Boru and the Battle of Clontarf have reached near-mythological import in Irish history, even as the specifics recede into mist. “The full events and exploits of that battle are known to God alone,” the Cogadh concedes, “for everyone else who was acquainted with them fell there together.” MH

Don Hollway wrote “Bohemian Catastrophe” (January 2018), about the 1620 Battle of White Mountain. For further reading he recommends the medieval texts Cogadh Gaedhel re Gallaibh (War of the Irish and Foreigners) and the Njáls saga, both available free online.