This book examines the early decades of economic nation building in Ireland. It draws on a large amount of previously unstudied archival material to construct a novel contribution to Irish business and economic history that focuses on government relations, business power and wider dynamics of power in a decolonising context. The book adopts a different approach to the early decades of Irish independence, decentering the typical focus on party political developments, Church-state relations and Anglo-Irish relations. Instead, the book explores the role of Irish businesses and services and their engagement with the governing elites of the time. More than just offering a general survey of Irish businesses in the early years of independence, the chapters of this book illuminate and analyse the ‘commanding heights’ of the economy, the Marxist term for the core distribution channels of capital and labour. In particular, the book focuses on four key strategic sectors – banking, insurance, shipping and rail – to analyse the tensions between the new Irish nationalist political elite and embedded business interests from the pre-independence era, how these led to the transformation of the Irish economic model by the late 1950s, and its gradual integration into a newly globalising world economy. This book will be essential reading for students and researchers of economic and business history, and Irish history and independence broadly.