When exploring Dublin history archaeological digs show evidence of civilization in Dublin as early as 7500 BC. Neolithic farmers and herdsmen came to Dublin in the 4th millenium BC and built monumental tombs such as those found at Newgrange.
Around 700 BC the Celts arrived and there was little change for over a 1000 years. St Patrick arrived in AD432 and brought Christianity to Ireland and the Celts were quick to embrace the religion. During the golden age of Celtic Christianity the Dublin area was home to several churches and the present day St Patrick’s Cathedral is where the saint baptized converts around AD450. This era produced high levels of Christian scholarship, resulting in such treasures as the elaborately decorated Book of Kells.
The city’s modern gaelic name of ‘Baile Atha Cliath’ derives from a Celtic settlement on the north bank of the River Liffey. Known then as Ath Cliathe (the ford over the hurdles) it was the only crossing over the river and lay at the junction of four major roads. It was the community at Ath Cliathe that bore the brunt of the island’s first naval invasion by the Vikings.
Norse Vikings established their first harbour in Dublin in AD841 and left in AD902, under pressure from local chieftains. They returned 15 years later and built a stronghold situated between the present location of Dublin Castle and Wood Quay. It was here that the rivers Liffey and Poddle converged in a body of dark, still water which the Vikings called Dyfflin or Dubh Linn (meaning ‘black pool’)
In 919 at the battle of Dublin the Vikings fended off the King of Tara and by the mid 1100s they started to intermarry with the Celts. The Vikings were then defeated at the battle of Clontarf in 1014 by Brian Boru, the Irish High King. Under King Sitric the Silkbeard, Dublin became a Christian vassal state. He oversaw the construction of a wooden cathedral (later rebuilt as Christ Church). By this time the population of Dublin was around 5000.