The Irish Civil War followed soon after the War of Independence.The history of Northern Ireland has since been dominated by sporadic sectarian conflict between (mainly Catholic) Irish nationalists and (mainly Protestant) unionists.This culture apparently prospered, and the island became more densely populated.Near the end of the Neolithic new types of monuments developed, such as circular embanked enclosures and timber, stone and post and pit circles.It is argued this is when the first signs of agriculture started to show, leading to the establishment of a Neolithic culture, characterised by the appearance of pottery, polished stone tools, rectangular wooden houses, megalithic tombs, and domesticated sheep and cattle.
Protestant domination of Ireland was confirmed after two periods of war between Catholics and Protestants in 1641--91.
As the period progressed, inhumation burial gave way to cremation and by the Middle Bronze Age, remains were often placed beneath large burial urns. The period between the start of the Iron Age and the historic period (431 AD) saw the gradual infiltration of small groups of Celtic-speaking people into Ireland, It is also during the fifth century that the main over-kingdoms of In Tuisceart, Airgialla, Ulaid, Mide, Laigin, Mumhain, Cóiced Ol n Echmacht began to emerge (see Kingdoms of ancient Ireland). The society of these kingdoms was dominated by an upper class consisting of aristocratic warriors and learned people, which possibly included Druids.
Linguists realised from the 17th century onwards that the language spoken by these people, the Goidelic languages, was a branch of the Celtic languages.
As the military and political defeat of Gaelic Ireland became more pronounced in the early seventeenth century, sectarian conflict became a recurrent theme in Irish history.
The 1614 overthrow of the Catholic majority in the Irish Parliament was realised principally through the creation of numerous new boroughs which were dominated by the new settlers.
The Bronze Age, which came to Ireland around 2000 BC, saw the production of elaborate gold and bronze ornaments, weapons and tools.