The Celtic-speaking people who lived in Ireland believed in the old Celtic gods.
Then, in about 432, a British monk St. Patrick went to Ireland to preach the Christian faith. Over the next 200 years, monasteries were founded throughout Ireland. The monks made beautiful copies of the Bible by hand.
About 1200 years ago, Irish monks made books by hand. They decorated their work with beautiful letters and pictures.
In the 700s and 800s, the Irish were some of the finest craftwarkers in Europe.
They made splendid brooches and cups of gold and silver, and were also famous for their stonework. The Irish were known as great storytellers, too.
In the 500s, and Irish monk called St Bredan is said to have sailed westwards to explores the lands around the Atlantic Ocean.
Tales about his voyages tell of islands, whales and volcanoes.
Ireland was divided into separate kingdoms.
Each ruler was supposed to recognize a High King as his chief, but the kings often quarrelled and fought with each other. In about 500, one northern group of Irish set up another kingdom called Dalriada, in western Scotland.
Brian Barú became High King of all Ireland in 1002.
He fought many battles with other Irish kings. He also fought against invaders from Scandinavia, the Vikings. Brian Ború defeated all his enemies at Clontarf in 1014, but was murdered after the battle.
The battle of Chantarf marked the end of Vicking power in Ireland.