Clonalis House is the Ancestral Home of the O'Conors, Kings of Connacht and at various times, High Kings of Ireland. Guests at Clonalis House can experience the unique atmosphere of this beautiful family home whilst enjoying heritage accommodation combined with the comfort of modern living.

But the O'Conors, as the ruling dynasty of Ireland's Western Province, have not always occupied such comfortable residences through the ages.

Of their early residences (mostly of wooden construction) nothing remains except references in the Annals of Ireland and in ancient Irish Poetry but sites at Rathcroghan/Carnfree, near Tulsk, Co Roscommon were important ceremonial places from the 5th Century AD onwards.

At the height of O'Conor power, as High Kings of Ireland in the 12th Century AD, Tuam and Dunmore both in Co Galway were their Ecclesiastic and Administrative centres. O'Conor Castles from the 14th century AD can be found in Ballintubber, Co Roscommon and in Roscommon town. The former Castle is still owned by the family although they have not resided there since the 17th Century.

The introduction of the Penal Laws (laws principally designed to economically disadvantage those not members of the Established Church) in the late 17th/18th centuries, devastated the fortunes of the O'Conors who remained fervently Catholic. The O'Conors like many of their co-religionists were driven into peasantry and Denis O'Conor (1674-1750) lived in a bahaun or peasants mud cottage in Kilmactranny Co Sligo for many years. In 1720 the same Denis recovered some 600 acres of land at Ballanagare, Co Roscommon where he built a small residence, the ruins of which are still visible just outside the village.

In 1820 the 'Ballanagare' O'Conors succeeded to the O'Conor estates at Clonalis when the 'Clonalis' branch of the Family became extinct in the male line and with this the Ballanagare O'Conors succeeded to the 'O'Conor Don' title. The title applies to the Chieftain of the O'Conors of Connaght and is one of a few titles specifically recognised under Irish Law as the Irish State is a Republic.

The 'New' Clonalis House was constructed by The Rt Hon Charles Owen O'Conor Don MP HML in 1878 to the design of the well known Victorian architect Pepys Cochrell. This property replaced an earlier residence on Clonalis Estate dating from approximately 1750, which the family considered unhealthy by the late 19th century, as it lay close to the banks of the River Suck and frequently flooded.

The 'New ' House combines characteristics of both Queen Anne and Italianate architectural styles. Contrary to the perception of Victorian architecture as being rather dark and gloomy the main reception and bedrooms of Clonalis all face south west and with large windows capture all available light, making the property a bright and airy residence.

The 'New' Clonalis House now serves the dual purpose of being a family home and a major repository of heritage and history, containing correspondence, heirlooms, objet d'art and portraits of the O'Conors over the past 600 years. The Clonalis Library, containing some 7000 volumes, is widely considered to be one of the best collections in private ownership in Ireland.