St Kieran's was founded in Kilkenny in the diocese of Ossory in 1782 - the year of the Relief Act itself - as the first Catholic secondary school established in Ireland under the new law. It was named after St Ciarán of Saigir, called in the Latin records Primogenitus Sanctorum Hiberniae, the first-born of the saints of Ireland, who established a monastery in what is now County Offaly in the early fifth century, possibly before St Patrick. The college trained men for the priesthood - some six hundred of its graduates would be ordained for service in the United States alone - and unlike Maynooth College, which received British government grants, St Kieran's was supported entirely by Irish Catholic donors. For 212 years the seminary trained priests; in 1994, with vocations in steep decline, Bishop Forristal closed it. The school continues as a Catholic secondary day school.

Thomas MacDonagh taught at St Kieran's from 1901 to 1903. Francis Sheehy Skeffington taught there from 1900 to 1901. Thirteen years later, in May 1916, both men were dead. MacDonagh was one of the seven signatories of the Proclamation of the Irish Republic and a commander in the Easter Rising; he was court-martialled and executed by firing squad at Kilmainham Gaol on 3 May 1916. Sheehy Skeffington - a pacifist, suffragist and journalist, who had taken no part in the Rising and was attempting to prevent looting during the fighting - was arrested by a British officer, Captain John Bowen-Colthurst, and executed without trial on 26 April. His murder caused political scandal; Bowen-Colthurst was eventually court-martialled, found guilty but insane, and detained briefly at Broadmoor before being quietly released. Two former teachers from a quiet Kilkenny seminary, dead in two different ways at the hands of the same army.

St Kieran's has won the All-Ireland Senior Colleges Hurling Final twenty-six times - more than any other school in Ireland. The next closest school is some distance behind. The college has also taken 55 Leinster Senior Colleges titles, 39 Leinster Junior titles and 34 Leinster Juvenile titles. The school's hurling tradition is so entrenched in Kilkenny's identity that the county team's success - Kilkenny hurlers have won more senior All-Ireland titles than any county - feeds back into the school's pool of recruits, and vice versa. The playwright Thomas Kilroy played hurling for St Kieran's and captained the team in 1952 before going on to write some of the most acclaimed plays of late twentieth-century Irish theatre.

Ralph Fiennes, the English actor whose grandfather lived in County Kilkenny, attended St Kieran's. Tomm Moore - the Kilkenny-based filmmaker behind The Secret of Kells and Song of the Sea, Oscar-nominated twice - studied here too, and his Cartoon Saloon animation studio is still in Kilkenny. Phil Hogan, who served as European Commissioner for Agriculture and Trade, was a pupil. So was Raymond Crotty, the economist whose 1985 court case against the Irish government's ratification of the Single European Act established the constitutional principle that any significant European treaty change in Ireland must be approved by referendum. Patrick Neary, who as Financial Regulator presided over the Irish banking system in the years leading to its 2008 collapse, also passed through here. The school has produced bishops, hurlers, and one Australian rules footballer.

On the campus, in a room named for him, are the papers of Canon William Carrigan - the Kilkenny priest who in 1905 published the four-volume History and Antiquities of the Diocese of Ossory, still the indispensable source on medieval and post-medieval Kilkenny ecclesiastical history. Carrigan died during the 1918 flu pandemic before he could finish a planned second edition; the materials he collected for that revision are also here. So are the papers of several Kilkenny families: the Wandesfordes, the Aylwards, the Smithwicks (yes, the brewers), the Swift Heaths and the Catherine Lanigan collection. The Glanbia Collection holds the original records of more than thirty village creameries - small Kilkenny cooperatives founded around 1900 that merged in 1966 to form Avonmore, and then in 1997 with Waterford Foods to form Glanbia, now a multinational nutrition company with operations in 34 countries. The dairy industry of Munster begins, in paper form, in this room.

St Kieran's College sits on College Road in Kilkenny, a handsome cut-stone Victorian Gothic building with later additions. From 1997 to 2018 Maynooth University ran its Kilkenny Campus here, in the west wing, offering BAs in Local Studies and Community Studies and graduating students for two decades before the programme closed. The school still hosts Coláiste Pobail Osraí, Kilkenny's Irish-language medium secondary school, and provides space for vocational training. On match days in autumn the playing fields at the back fill with green and white jerseys; the school colour is green, against the county's black and amber. Out the front, the motto on the crest still reads in Latin what the founders meant in 1782: that something that had been impossible was now possible. The winter has passed.