Westport House stands on the Carrowbeg River near Clew Bay in County Mayo. The present house was begun in the eighteenth century for the Browne family on or near an earlier O'Malley stronghold. Family tradition connects the estate with Grace O'Malley, the sixteenth-century maritime leader, through her descendants. Architects including Richard Cassels and later James Wyatt contributed to the evolving design, producing a residence shaped by several campaigns rather than one fixed moment.

The Brownes became earls of Altamont and marquesses of Sligo, managing extensive land and using the house for family life, politics, hospitality, collecting, and estate administration. Its architecture, contents, gardens, lake, terraces, farms, and planned approaches depended on tenants, servants, builders, gardeners, craftspeople, and laborers. Estate wealth existed within the unequal structures of landlordism and the British Empire, and the family's social position cannot be understood only through elegant interiors.

Howe Peter Browne, second marquess of Sligo, became governor of Jamaica after slavery had been legally abolished in the British Empire. He challenged abuses within the apprenticeship system and supported earlier full freedom, while also belonging to an aristocratic family embedded in imperial property and privilege. At Westport, famine, poverty, tenancy, and emigration affected surrounding communities during the nineteenth century. These histories complicate any purely celebratory account of benevolent ownership.

The family retained Westport for generations and opened the house and grounds to visitors in the twentieth century, developing attractions to support maintenance. After financial pressure, the estate passed to new local ownership in 2017. A large redevelopment program now combines conservation, hospitality, recreation, and landscape work. The house is currently closed during transformation, while parts of the wider estate remain active. Modern commercial uses must be clearly distinguished from the historic residence and designed landscape.

Westport House is significant for its architecture, O'Malley and Browne associations, landlord and imperial histories, collections, and evolving relationship with the town. Interpretation should include tenants, servants, famine-era communities, women, emigrants, and workers alongside titled owners. Conservation must address roofs, stone, interiors, collections, river flooding, trees, archaeology, visitor infrastructure, and new construction. Transparent documentation can ensure that redevelopment protects historic evidence rather than converting the estate into a generic leisure setting. Public interpretation should also address the estate's recent ownership change and construction honestly, because preservation and commercial reinvention are happening simultaneously. Archaeological safeguards, independent heritage review, and accessible reporting can help ensure that economic renewal benefits the town while retaining evidence of tenancy, famine, empire, and domestic work.