During discussions for the Government of Ireland Act 1920, Northern Ireland as we know it was created. However, there were discussions of the Irish boundary line, including partitioning the full province of Ulster. This raises a fundamental 'what if' within Irish Studies, could Ulster Unionists have controlled nine-county Northern Ireland? This a counterfactual history to mark the centenary of the 1925 Irish Boundary Commission, as a reflection of the impact of partition, and subsequent questions of what the knock-on impact would have been. In particular, how would this altered timeline affect the border counties? Could Ulster Unionists have controlled Monaghan County Council? Would Border County Unionists have been able to return representatives to Stormont? How would a nine-county Northern Ireland have influenced the Battle of the Atlantic during World War II? These questions, and much more, will be answered in this work as it looks at how history could have taken a different turn.