This thesis uses the life of James Ryan (1892-1970) as a means by which to explore the emergence and development of the independent Irish state. As a figure who was at the centre of the foundational events of the independent Irish state from 1916 until 22, James Ryan became one of the central policy-makers in the Irish state during its early decades, serving as Minister for Agriculture, Health, Social Welfare and Finance at crucial junctures for each of these areas. Ryan has nonetheless remained an underappreciated figure in Irish historiography. This research will address this obvious historiographical shortcoming by examining the formation and evolution of this key policy-maker. As a revolutionary whose centrality in the Irish Revolution resulted from his medical background and membership, along with his sisters and wife, of the most prominent family of the Irish Revolution, Ryan’s experience was unique. This research explores the intersection of medicine and revolutionary activism and offers a fresh perspective on the role of women in the Irish state. Furthermore, this research examines how this revolutionary zealot, who was once unyielding in his idealism and disdainful of compromise, evolved into a pragmatic politician guided by realism. In an eventful ministerial career, Ryan oversaw Irish agriculture and food security during existential crises in the 1930s and 1940s, the foundation of the Departments of Health and Social Welfare, and the economic transformation of the 1960s. His extraordinary career offers an unprecedented opportunity to analyse policy evolution over several decades. Employing an array of Irish and international archives, this PhD challenges the prime ministerial fixation that has dominated the literature and provides a more insightful approach to understanding policy developments in independent Ireland.