Well into the 19th century, archeology in Ireland was included under the umbrella term “antiquarianism”, which also included philology; the collecting, transcribing, translating, and editing of medieval Irish manuscripts; and the collection of folklore. Despite this, many antiquarian societies formed in the course of the century carried the word “archeological” in their titles, such as the Irish Archaeological Society (founded in 1840, merged in 1854 with the Celtic Society to form the Irish Archaeological and Celtic Society) and the Kilkenny Archaeological Society (founded in 1849). Many antiquarians, such as Sir William Wilde, Robert Shipboy MacAdam, and George Petrie, focused much of their research on Ireland’s physical remains, though they had other interests as well. There were several journals dedicated to the archeology of Ireland, Transactions (later Proceedings) of the Royal Irish Academy and the Ulster Journal of Archaeology, though these also included articles of a more antiquarian nature.

Irish archeology can be traced back to the mid-17th century (James Ware’s two books on Ireland and its antiquities). Thomas Molyneux, a Dublin physician, published some pieces in the 1720s on what were then called Danish remains in Ireland – ringforts and the like; he was also one of the first scholars to provide a plan to the important site of Newgrange. Later that century, Charles Vallancey, amidst his speculative works on the ethnic origins of the Irish and of the Gaelic language, published on the origins and functions of round towers in the journal Collectanea de rebus Hiberbernicis (founded in 1770). Other antiquarians examining round towers at this time included Edward Ledwich and Charles O’Conor – the former arguing for Danish origins; the latter for druidical. Debates over the origins of round towers would last until the mid-19th century; the matter was settled by George Petrie, known as the father of scientific Irish archeology, who argued for the round towers’ medieval Irish ecclesiastical origins. Petrie published on Ireland’s ecclesiastical archeology, as well as a comprehensive survey of the Hill of Tara. He was the leader of the topographical or historical section of the Ordnance Survey of Ireland, which, undertaken in the 1820s, went beyond mere cartography to include antiquities in the landscape alongside extensive research into the history and meaning of Irish place names. Petrie was aided in his efforts by John O’Donovan and Eugene O’Curry. He helped to expand the antiquities held in the library of the Royal Irish Academy considerably, collecting many manuscripts and artefacts, such as the Cross of Cong. This collection was catalogued by William Wilde in the 1850s before it was eventually transferred to the newly formed National Museum of Ireland in 1890. During the mid-century, research was also carried out on inscriptions in ogham runes (by John Windele and Charles Graves). The interest in Irish ecclesiastical history in these decades led to a popularization of works by the likes of the Earl of Dunraven and the first woman to feature prominently in Irish archeology, Margaret Stokes. Thomas Johnson Westropp has been described as the last of the great gifted amateurs working on Irish and British prehistorical remains.

The professionalization of archeology commenced in 1854 when Eugene O’Curry was appointed to the chair of archeology and Irish history in the newly-founded Catholic University of Dublin – the first post in Ireland and occurring only four years after the first post in the British Isles in Cambridge. Although O’Curry was a philologist, his posthumously published The manners and customs of the Ancient Irish dealt with some of Ireland’s physical remains. Of particular importance to the emergence of archeology from antiquarianism was C.J. Thomsen’s three-period classification system, introduced in Ireland by Thomsen’s colleague Jens Jacob Asmussen Worsaae on his visit to Ireland in 1846-47. Professionalization was a slow process, which can be measured in the increasing number of learned archeological societies, and was completed by the creation of two chairs in archeology in Irish universities in 1909: University College Dublin and University College Cork. This meant that there would be training for future archeologists, consolidating the move away from speculators and amateurs. The field of early Irish philology likewise became more academically factualist and methodologically systematic as a result of continental influence starting from Johann Caspar Zeuss’s Grammatica Celtica (1854) and resulting in the creation of several chairs. This development was championed by Margaret Stokes’s brother Whitley Stokes.

Cultural nationalism in Ireland played upon the notion that the early Middle Ages had been Ireland’s golden age. Research into artefacts drew attention to Ireland’s long history and glorified its early refinement. Investigations into sites associated with Irish kings, such as the Hill of Tara, served to reinforce awareness of Ireland’s sovereignty before the 12th-century arrival of the English. Material remains from medieval Ireland such as the Tara Brooch were popularized and inspired copies and a “Celtic” jewellery design. The mausoleum of the nationalist leader Daniel O’Connell featured a replica round tower. By using archeological remains, Eugene O’Curry demonstrated that several swords in the library of the Royal Irish Academy belonged to the mythical Fir Bolgs and the Tuatha Dé Danaan; William Wilde used John O’Donovan’s edition of an ancient, legendary hero-tale to aid him in his investigation into what he thought was the actual site of a prehistoric battle. Ethnographical notions of identity were also activated here as in other parts of Europe: Wilde’s research into the skulls of what he deemed the Fir Bolgs and the Tuatha Dé Danaan would be used to help claims concerning an Irish or Celtic race. Similarly, material artefacts and textual remains were drawn upon, not only for national but also for denominational loyalties of the day. When appointing O’Curry to the chair of Irish history and archeology, John Henry Newman (rector of the new Catholic University) made it clear that he expected O’Curry to make explicit reference to the “Catholicity” of the language, manuscripts, and remains of ancient Ireland.

As the field became more professional, links between archeology and cultural nationalism, particularly the supposed proof of Ireland’s mythical past, diminished, its role in this respect being taken over by literary and mythological forms of antiquarian interest.