It is traditionally rooted in the medieval period, and is also evidenced in Irish immigration to North America, South Africa, Australia, New Zealand and Great Britain. Anti-Irish sentiment can include both social and cultural discrimination in Ireland itself, such as sectarianism or cultural religious political conflicts in the Troubles of Northern Ireland.
The negative stereotyping of the Irish began ca. 1190 with the Norman chronicler Giraldus Cambrensis, also known as Gerald of Wales. To justify the Norman invasion of Ireland, he wrote disparagingly of the Irish. "Gerald was seeking promotion by Henry II within the English church. His history was therefore written to create a certain effect—of supporting Henry II's claims to Ireland."
Over the centuries, hostility increased towards the Irish, who steadfastly remained Roman Catholic in spite of coercive force by Edward VI and subsequent rulers to convert them to Protestantism. The religious majority of the Irish nation was ruled by a religious minority, leading to perennial social conflict. During the Great Famine in the middle of the 19th century, some evangelical Protestants sought to convert the starving Catholics as part of their relief efforts.