This thesis traces the economic, social, political and cultural aspects of the Protestant community in Sligo from the outbreak of the First World War in 1914 to the declaration of an Irish republic in 1949. In the immediate period before the First World War the Protestant community in Sligo were predominantly unionist and were well organised and vocal in their opposition to Home Rule. The strong commitment of Protestants and unionists to the war effort weakened the unionist movement in Sligo. The inability of the Sligo unionists to reactivate their movement after the war and their refusal to reach any accommodation with moderate nationalists resulted in the alienation of many Protestants from the Catholic and nationalist majority. However, by 1949, Sligo Protestants had pragmatically adapted to the changes in the period and had ditched unionism in favour of more economic and interestbased political parties. They had weathered well the difficult periods of the War of Independence and the Civil War and few Sligo Protestants suffered hardship in the period from 1919 to 1923. The change from British administration to an Irish one was not disastrous for Sligo’s Protestant population and two-thirds had remained in Sligo after the Civil War and they continued to take an active interest in, and make a large contribution to both the political and economic life of Sligo. In so doing they were able to argue their points of view and were able to work together with Catholics and nationalists, while still being able to honour their heritage and traditions and remaining loyal to their own groups and clubs which gave rise not only to a socially healthy community with a feeling of belongingness to a new state, but also a community with a sense of a separate identity.