The first settlement of Ireland took place sometime around 6000 BC by hunters and fishers along the island's eastern coast. The Gaels, a Celtic-speaking people from western Europe, found their way to the island sometime between about 600 and 150 BC and subdued the previous inhabitants.
About the time of Christ the island was organised into five kingdoms, the traditional "Five Fifths of Ireland". By AD 400 seven independent kingdoms had evolved. The kings of these kingdoms often allied their armies to raid neighbouring Roman Britain and the Continent. On one of these raids a lad of 16 was captured, returned to Ireland and sold into slavery. During his enslavement the boy turned to religion and some six years later at the age of 22 escaped. The young man studied theology in the Roman church and in 432 returned to Ireland, and began a lifelong quest of converting the Irish to Christianity. This was none other than Ireland's patron, Saint Patrick.