A year after Setanta joined the Boy’s Troop, a renowned smith named Culann came to Emain Macha and invited King Conchobar mac Nessa to a feast at his home.

Culann was a master craftsman but not a wealthy man, so he asked the King to bring only a small group of guests. Conchobar agreed and set off with a small retinue. On the way, he passed a field where the Boy’s Troop were playing games.

Setanta was at the heart of the competition. In one game, the boys tried to snatch each other’s cloaks, and by the end, Setanta stood victorious with a great heap of cloaks at his feet, while his own remained untouched. In another game, where each boy tried to knock the others off their feet, Setanta was the last one standing.

Then, the boys played hurling—but it was clear that the game had turned into Setanta versus everyone else.

Watching from a distance, Conchobar called out and invited Setanta to join them at Culann’s feast. But the boy refused—he wasn’t finished playing yet.

The King understood and asked if Setanta knew the road to Culann’s house so he could follow later. The boy admitted he didn’t, but he was confident he could track the King’s chariots.

And so, Conchobar rode on with his men, arriving at Culann’s house, where they were welcomed with a grand feast.

As the guests settled in, Culann asked if the King was expecting anyone else.

He explained that, living so far from Emain Macha, he had no warriors to protect him. His only defence was his great guard dog—a beast the size of a pony, trained from birth to attack anyone but its master.

Forgetting all about Setanta, Conchobar assured Culann that everyone was present.

With that, Culann unleashed the hound. The great beast patrolled the land, checking for intruders, then lay down at the door, its massive head on its paws, red eyes glowing in the night.

Meanwhile, Setanta finished his game and set off to follow the King’s trail. To pass the time, he played his usual game of skill—throwing his ball into the air, striking it with his hurley, and then chasing after it to catch it before it hit the ground.

As Culann’s hound spotted the boy approaching, it let out a ferocious roar that echoed for miles.

Inside the feast hall, silence fell.

Everyone knew what that roar meant—the beast had found an intruder and was about to tear them apart.

In that moment, Conchobar’s heart sank—he had completely forgotten about Setanta.

The boy turned to face the charging hound, but he was armed with nothing but his hurley stick and his ball.

Thinking fast, Setanta struck the ball with all his might, sending it flying straight into the beast’s open mouth. It lodged in the hound’s throat, choking it. As the animal struggled, Setanta grabbed its hind legs, swung it with all his strength, and dashed its brains against a rock.

At that moment, the feast hall emptied as Conchobar and his men rushed outside.

They expected to find the great hound standing over Setanta’s lifeless body.

Instead, they found Setanta alive and victorious. The people of Emain Macha rejoiced.

But Culann wept.

His faithful hound—his only protector—was dead. Though the King and his family were welcome in his home, Culann refused to let Setanta enter.

Conchobar bristled at the insult, but Culann was devastated. His livelihood was ruined—without the hound, he had no defence against thieves or enemies.

Setanta felt terrible for what he had done.

“I will make it right,” he said. “Is there a pup of that hound anywhere in Ireland?”

Culann admitted there was a young pup, but it would take years to train. What was he supposed to do in the meantime?

Setanta did not hesitate.

“Train the pup as you did before. Until it is ready, I will guard your home myself.”

That night, the druid Cathbad was listening. He spoke a prophecy:

“From this day forward, Setanta shall be known as Cú Chulainn—Culann’s Hound. One day, his name will be spoken by every man in the world.”

Setanta accepted the new name.

And for the next year, when night fell, he left Emain Macha, walked to Culann’s house, patrolled the land, and lay down at the door to sleep like a hound—one eye open, watching for threats.

Thus, Setanta became Cú Chulainn—the Hound of Ulster.