Modern Ireland is a society formed by colonization. Twice, in the twelfth and thirteenth centuries and again in the sixteenth and seventeenth, military conquest and the planting of foreign settlers changed forever the demographic makeup of the population, and with it the language, the culture, the religion and the social and political structure. At the same time, there were features that set Ireland apart from other examples of settler colonialism. The settlers traversed a short distance, so their movement could be credibly presented either as the establishment of a colony or as the reclamation and integration of an underdeveloped periphery. The indigenous population among whom they settled, in contrast to those encountered by other colonists, was both white and Christian. Most important of all, the second major colonization coincided with the partition of Europe along confessional lines. In Ireland, this came to mean a society in which two deep lines of division, between settler and native and between Catholic and Protestant, were partially but imperfectly aligned, creating the context for repeated shifts in identity and allegiance.