The Táin Bó Cúailnge (“The Cattle Raid of Cooley”) is the central epic of the Ulster Cycle and the greatest prose narrative in early Irish literature. At its heart stands a young man, still a boy by some reckonings, who single-handedly defends his province against an entire army. His name is Cú Chulainn — the Hound of Culann — and in the long months of the Táin he becomes the embodiment of Ulster itself: stubborn, brilliant, doomed, and undefeated.
The Táin is preserved in two recensions, known as Recension I (in the Book of the Dun Cow, c. 1100) and Recension II (in the Book of Leinster, c. 1160), together with fragments in later manuscripts. The text as we have it was written down by Christian monks in the eleventh and twelfth centuries, but the underlying story is much older, perhaps reaching back to the iron age. The setting is the Ireland of the first century CE, an Ireland of provincial kingdoms, druidic curses, and great cattle herds.
The Cause of the War
The war begins with a quarrel between two queens, both of them great in their own right. Medb, the warrior-queen of Connacht in the west, is wife of Ailill mac Máta. He is the king, but she is the greater of the two. Ailill boasts one night that he has no equal among women; Medb, furious, finds that the only possession she has but her husband lacks is a great white-horned bull from the south. She then learns of a still greater bull, the Donn Cúailnge, the brown bull of Cooley, in the northern province of Ulster, and she determines to take it.
To do so she raises a great army of Connacht and beyond, including the three Collas, the seven kings of Meath, the exiles of Leinster, and the warriors of the western isles. She also brings into her host the most dangerous ally of all: Fergus mac Róich, the former king of Ulster, who has been exiled from his home province in a dispute with Conchobar mac Nessa and has wandered the roads of Ireland with a band of three thousand warriors ever since. Fergus is Cú Chulainn’s foster-father; he has taught the boy all he knows of war. To the Ulstermen Fergus is the man they would have chosen for king, and his appearance in the camp of Medb is itself a sign that no ordinary war is coming.
The Curse of Macha
When the host of Connacht enters Ulster, it finds a province strangely silent. The warriors of Ulster — the men of the Red Branch, the champions of Emain Macha, the very flower of the northern people — are not on the roads to meet them. They are in their beds, struck down by a curse older than the memory of the present age. Macha, the divine sovereignty goddess of Ulster, had at some time in the dim past cursed the men of the province to feel, for nine generations and five (or, in some versions, nine) of every ninth year, the pains of a woman in labor, in punishment for an old wrong. The curse was about to strike, and the warriors of Ulster lay writhing, unable to fight, unable to rise, unable even to lift a weapon.
Only one person in Ulster is unaffected: the boy Cú Chulainn, who is not an Ulsterman by his geasa (he is, by the reckoning of his mother Dechtine, a man of the southern province, and therefore not bound by Macha’s curse). It is therefore to him, alone, that the defense of Ulster falls.
The Hero’s Single Defense
Cú Chulainn’s defense of Ulster is one of the most remarkable set-pieces in early European literature. He ranges the borders of the province in his war-chariot — the great black horse Liathan Macha and the brown horse Sainglain drawing a chariot of hammered bronze and silver — and meets the host of Medb in a series of single combats, feints, and tricks. He does not fight every day; the prose says that he “halves” each year, fighting for a quarter and resting for three, but in the texts we have the defense is a continuous round of encounters.
The tactics vary. Sometimes he meets the army of Connacht at a ford, in single combat, killing champion after champion in formal duel. Sometimes he sends a warning by druidic message, or disguises himself, or lies in ambush in the form of a young deer, a hound, or a phantom warrior. Sometimes he simply rides out alone into the camp of Medb at night and slays a hundred of her warriors in their beds, returning before dawn with a heap of severed heads. In one famous episode, he takes the form of a monstrous foreigner with a crest of hair from ear to ear, a gray cloak of two hundred threads of matted hair, a long-headed spear in one hand, a venomous hound at his back, and a forked pole-arm in the other — a figure of pure dread.
In these encounters he uses the Gáe Bolga, the spear of bone and silver he learned from Scáthach. The Gáe Bolga is the most feared weapon in Irish legend: when Cú Chulainn thrust it into the body of an enemy it split into thirty barbs that could not be removed without opening the corpse. He also uses the salmon-leap, a flying kick delivered with such force that it breaks the spine of a man, and the hero’s light — a column of dark blood and a red mist that obscure him in battle.
The Slaying of Fer Diad
The most poignant episode of the Táin is the death of Fer Diad, Cú Chulainn’s foster-brother, who has been raised alongside him by Scáthach in Alba and is the only warrior in Ireland who is his equal. Fer Diad, an exile from Ulster, has joined the host of Medb after his foster-father Fergus promised him that no harm would come to him. When he is sent to fight the boy-hero, both men weep the night before the battle. Cú Chulainn offers him feasts, gifts, and finally, a return to the Ulstermen with the honors of a king. Fer Diad refuses: he has given his word, and a champion’s word is his life.
For three days the two fight from the fords of Ulster, wading waist-deep in cold water, and on each of the first two days they part unharmed. On the third day Cú Chulainn, knowing that ordinary weapons will not pierce his foster-brother’s body, uses the Gáe Bolga. He leaps into the air and strikes downward with the spear; the barbs of the Gáe Bolga pass through Fer Diad’s body in a single stream. As his foster-brother dies, Cú Chulainn is reported to have said: “O Fer Diad, the friend of my soul, the comrade of my company, the heart of my counsel, the pledge of my honor, the one who has my back in the press of battle — it is not against you I have fought; it is against the women of the Sidhe who have forced me to this.” The scene has been read as the Irish counterpart of the duel of Achilles and Hector at the gates of Troy, but its tone is older, more bitter, more like a quarrel of friends.
The Death of the Bull and the End of the War
The Táin ends not with Cú Chulainn’s death but with the death of the great bull. The Donn Cúailnge, taken at last to Medb’s camp in Connacht, fights the Findbennach (“the White-Horned”), the bull of Ailill, in a combat that lasts a day and a night. The Findbennach is killed first; the Donn Cúailnge, triumphant, roars across Ireland from Connacht to his native Cooley, and falls dead of his wounds. The war has been for nothing: the bull of Cooley is back in Cooley, the bull of Connacht is dead, and the warriors on both sides are broken.
The Cú Chulainn cycle is its own thing, the creation of a society that found its deepest image of the human in the figure of the young man who fights alone. The Old Irish of the Book of the Dun Cow has a savage clarity unmatched in medieval literature, and Cú Chulainn is its model for every later defense of a small country against a great empire.
Last reviewed: June 2026.