This paper offers a historical perspective on government policies for the rationalisation of higher education (HE) in Ireland through a critical re-appraisal of the initiative for "merger" of Trinity College and University College Dublin. The initiative launched by Donogh O'Malley in 1967 was the first significant attempt by an Irish government to transform the institutional architecture of HE. This study sheds new light on the rationale for merger. A key motivation for the merger was to overcome "the problem of Trinity College Dublin": policy-makers sought to integrate Trinity College, long regarded as a Protestant "enclave" in a predominantly Catholic society, within the Irish HE system. O'Malley's initiative sought to bring Trinity College Dublin (TCD) firmly under the control of the state and transcend traditional religious divisions, by circumventing the "ban" on the attendance of Catholics at TCD imposed by the Catholic bishops. This paper also explores the emergence of proactive, interventionist approaches by Irish ministers and officials to policy formulation and implementation in HE.