This chapter analyses the significance of Ireland within far right thought from the Anglo-Irish War to the Troubles. It will demonstrate that the loss of Ireland, the majority of which became autonomous following the Anglo-Irish Treaty in 1921, was a traumatic event for the far right and crucial in shaping early narratives of British imperial decline. As the salience of Ireland as a political issue weakened, Oswald Mosley and the British Union of Fascists then sought to cultivate the support of the Irish diaspora and their descendants in Britain through an ambiguous stance, particularly on Ulster, reflecting a divergence between themselves and the unionist right. Following the Second World War, Mosley and the UM went a step further, advocating a united Ireland, angering many others on the far right. At the outbreak of The Troubles in 1969, the largest far right party, the National Front, exhibited a staunchly pro-unionist position and a series of draconian policies they claimed would end ethnic violence in Ireland. Despite this, Ireland reflected a difficult issue for the far right to navigate throughout the twentieth century – never quite sure if the Irish were racial brethren or foes. Ultimately, following the trauma of Ireland’s move away from the United Kingdom and then, the Commonwealth, it was an issue that would cease to inflame the far right’s senses.