By the time political independence was achieved in the 1920s in Ireland, its national education system over the previous century had been underpinned by imperial ideology and values. In the early 1920s, curriculum planning was influenced by the post-revolutionary and post-war context and, unsurprisingly, placed an emphasis on building nationhood and a distinct Irish identity for the Irish Free State. Central to this curriculum planning was Rev. Professor Timothy Corcoran who acted as an external advisor to the 1922 and 1926 conferences that developed primary curriculum policy. This article explores and assesses the influence, impact and legacy of Corcoran through an analysis of his prolific writings as they related to the primary school curriculum. The analysis reveals that Corcoran's thinking, more than that of any other stakeholder in the era, was uniquely influential in determining the philosophy, content and pedagogies prevalent in primary schools in Ireland until the 1970s.