The aim of this thesis is to illustrate the impact of partition on the border counties of Cavan and Monaghan in the period 1914 to 1926. Partition had a profound impact on this region in political, economic and social terms. People from all walks of life in the region were adversely affected by the partition of Ireland which was brought about by the Government o f Ireland Act of December 1920. The period 1914-1920 which witnessed the imposition of partition was extremely fraught in Cavan and Monaghan as tensions mounted between nationalists and unionists over the regions future. This work examines these tensions and shows how sectarian animosities built up in the region. The reactions of different sections of the community to the partition settlement is also examined. The final imposition of partition ushered in an immensely turbulent period for the region as it coincided with the outbreak of the War of Independence. Sectarian tensions mounted and by 1920 open sectarian hostilities engulfed the region. These animosities in tandem with the Belfast Boycott created deep sectarian divisions. Another period of violence followed for residents of the region. This time, however, this violence took the form of border warfare. This work examines the open warfare which broke out between rival forces operating on either side of the borderline and its implications for Cavan and Monaghan. The final section of this thesis explores the economic and social ramifications of partition in depth. The final period under consideration, i.e. 1923-1925, witnessed the creation of fiscal seperation between North and South. The impact of this economic partition and the concurrent closure of border roads is analyized. Specific attention is given to the border towns which suffered the most from the creation of the customs posts. This work concludes with an examination of the changes which the Boundary Commission recommended for the region and the effect these changes would have had on the region.