This chapter examines the structure, the demise and landscape legacy of landlordism in the form of demesnes and big houses in County Cavan during the period c.1870 to c.1970. Within this time frame, the economic, social and political status, which the landowners - or landlords as they are commonly referred to - had occupied and enjoyed for several centuries, was gradually eroded. Tenant farmers became owners, facilitated by the introduction of numerous pieces of land legislation that removed from the landlords what was for many their primary revenue source, rent. Reduced economic circumstances, coupled with the political instability of the 1920s, left many former landlords feeling alienated and redundant in the ‘new’ Ireland. In County Cavan the crisis facing the landowners at this time was accentuated by the fact that many felt betrayed and abandoned by their former political allies in Unionism, as the border partition in Ireland was drawn. A minority of the landowners remained in their ancestral homes from the 1920s onwards working the demesne lands as intensive agricultural enterprises, while others left the county permanently. These landscapes and buildings are today important architectural and botanical components of County Cavan’s rich heritage.