This house was built by the Ormsby family in 1780/1790. Originally Jacobites, they were reinstated at the Restoration and given grants of land in Ireland by Charles II.

It was later purchased by William Flynn who ran it as a lakeside fishing hotel and was later eased to a Hercules Knox.

The Jesus and Mary Order of nuns founded their first branch at Errew in 1912 at the request of Bishop Naughton. Mother Regis O’Connor (Irish), Mother Gonzaga (Austrian), Mother Bertha (Austrian Cook), Mother Rasphael Musgrave (English) and Mother Sebastian (Irish) pioneered the venture. A French nun, Mother Henrietta Baudowin arrived in 1915. They purchased Gortnor Abbey in 1916 and set about converting it into a Convent boarding school.

Rev. Mother Stanislaus Ryan opened a Novitiate and began the first-storey building of the school in 1919. The second and third storeys were erected soon afterwards. Mother St. John McPhillips (Cork), Mother Fidelis Donegan (Cork) and Mother Patricia Gallagher (Crossmolina) were the first nun students in University College Galway in 1924.

Mother St. Veronica was headmistress of the Secondary School until 1928 when she was replaced by Mother St. John Phillips. A new extension in 1944 incorporated a Domestic Science room, extra dormitories for boarders, classrooms, cloakroom and music room. A new chapel, a dining hall and bedrooms for boarders were added in 1961.

Later, a new school was built on the grounds of the Convent with government aid and local contributions. In earlier years the Convent catered for girls only but in 1973 it opened its doors to boys as well. A phasing out of boarders took place during the 1980’s. There are many lay teachers also on the staff of today.