Archaeologists think the first people to settle in Ireland arrived around 6000 B.C. By 3500 B.C., settlers were using stone tools to clear farmlands. Around 700 B.C., a diverse and technologically advanced culture from central Europe called the Celts began to settle the island. They would thrive there for nearly 2,000 years.
In the ninth century A.D., Viking invaders began raids into Ireland. They established settlements that later became some of the country's main cities, including the capital, Dublin. The Vikings and Celts fought often for 200 years until a battle in 1014 united the country. Peace broke down quickly though, and Ireland was divided into many kingdoms.
In 1170, Norman Vikings who had taken control of England invaded Ireland and made it an English territory. In the early 1600s, England's official religion became Protestant while most Irish remained Roman Catholic. This would create tensions that would eventually lead to revolution and Ireland's independence.
By the 1820s, British laws unfair to Catholics had sparked a mass movement for Irish sovereignty. In 1829, many of those laws were overturned, but Ireland still wanted freedom. In 1922, after violent uprisings, the Irish Free State was created within the British Empire.In 1948, most of Ireland became an independent country, while six mainly Protestant counties in the northeast remained a British territory.