This thesis describes, details and maps the evolving patterns of landownership and landholding in, and the changing landscape of the barony of Demifore, county Meath during the period circa 1700 to circa 1830s. It traces the impact of the seventeenth century land settlements whereby the dominant Anglo-Norman landowning group was largely replaced by Cromwellian landowners and by other landowners from outside the barony, in particular, from Dublin. The thesis focuses on the largest landholders, namely those identified as holding 500+ plantation acres, who together owned over two-thirds of the barony. This was a diverse group, in terms of both their origins and the scale of the estates they held. While some of the landowners resided on their estates in the barony, others held their lands as absentee landlords. An evaluation of the estate management practices implemented by the landowners forms a central plank of this research, focusing on leasing policies, rental income and financial transactions. An assessment of the part played by the principal leaseholders and their influence on management practice is undertaken, revealing their central role in landholding during the period. While some of the research findings are based on surviving fragmentary estate and family papers, a significant proportion have emerged from a database compiled using a pioneering methodology in mining the memorials in the Registry of Deeds to their full potential. The research highlights how the ideals of ‘improvement’ impacted the barony during the period. Of particular note are the ‘big houses’ and their associated demesnes, constructed and laid down during the period, creating islands of aesthetically pleasing landscapes throughout the barony. The imposing mansion at Loughcrew belonging to the Naper family, the largest landowners identified in the barony, through to the more modest ‘big houses’ each conveyed the status, values and ideals of their owner. The reach of ‘improvement’ extended beyond the walls of the demesne into the wider countryside. The continuing importance of agriculture and, in particular, the part played by tillage and the associated mills as the focus of the local economy is also assessed. At the centre of this rural agricultural economy, the only town in the barony, Oldcastle, was gradually enlarged, modernised and improved during the period under the aegis of the Naper family, the urban tenants, the state and church, emerging as a significant market, educational and religious centre by the 1830s.