Táin Bó Cúailnge

The Tain Bo Cuailnge ("The Cattle Raid of Cooley") is an ancient Irish story. It is part of a group of stories, the Ulster Cycle or Cuchulain cycle. Ulster is a place in northern Ireland where most of the story happens. Cuchulain is the main hero of the story. According to Professor John Dunn of Catholic University, who wrote an English translation in 1914, the Tain is the Iliad of Ireland.
History
The Tain is the oldest vernacular story in western Europe, meaning the oldest story told in the language that people really spoke (instead of in Latin).
The story was passed down by people telling it out loud, so it may have changed many times. The oldest version of the Tain that to be written down is the Lebor na hUidre or Book of the Dun Cow. People at Clonmacnoise wrote it down in the 1100s c.e.
In ancient Ireland, cows were very important. Many of the stories people told were about catching or stealing cows from other people. According to a book written in 1088 c.e., the real-life King Conchobor, who is the king in the Tain, became king of Ireland in 30 c.e.
Story
In part of Ireland called Connacht, Queen Medb and King Ailil joke about which one of them is richer. They look at all their wealth to compare it, from the most valuable gold to the commonest cloth. They find they have almost exactly the same amount. Except King Ailil has one very good bull called Finnbeach ("White-horned"). Queen Medb is sad and disappointed. Then she hears there is a bull as good as Finnbeach nearby in Cuailnge, called Donn Cualnge ("Brown bull of Culange"). She sends her messenger Mac Roth, to the bull's owner and asks to rent it for a year. The owner agrees. But later that night, Medb's men boast that, if the owner had said no, Medb would have sent her army to take the bull by force. This makes the owner angry, and he sends the messenegers away without the bull.
Medb and Ailil take their army into to capture the bull.
The men of Ulster cannot fight back. In an earlier part of the Ulster Cycle, a goddess put a curse on them. For five days every year, warriors born in Ulster feel like they are giving birth to babies. Because of the pain, they cannot fight. However, one warrior was not born in Ulster: Cuchullain.
Cuchullain goes to Medb's army alone. At night, he attacks the sleeping soldiers with his slingshot, killing many. The next day, he makes a deal with Medb's army: They choose one warrior to fight him in one man against one man. If they do this, Cuchullain will not attack them at night. If Cuchullain wins, the army must stay still until the next day. If the other fighter wins, Cuchullain will die.
Medb agrees, saying that it is better to lose one warrior a day than twenty at night. To convince men to fight Cuchullain, Medb promises that anyone who kills him can marry her beautiful daughter, Finnabair. One of the men Medb sends is Cuchullain's foster-father, Fergus. Another is Cuchullain's foster brother and best friend, Ferdiad.
In this way, Cuchullain slows Medb's army almost until King Conchobor and the rest of the warriors feel better. Medb and her army capture many cows and women. Then the two armies fight.
The Ulster Army wins. Then Finnbeach and Dunn Culagne fight too. Dun Culagne wins, and parts of Finnbeach's organs are stuck on his horns. He walks down the river and some of the organs fall off. Different places on the river are named after where the organs fell off the horns.
Effects
Later writers read or heard about the Tain and it affected their own work. For example, it affected W.B. Yeats, Lady Augusta Gregory, Seamus Heaney, and Frank McCourt.