The transformation of the Irish economy from an amalgam of small semi-independent lordships into the beginnings of an integrated market economy is one of the main features of the early modern period. This pamphlet is the first work in almost a century to document and explain the processes by which this change occurred. It examines such central themes as the growth of population, the changes in property rights, the redistribution of land and the impact of commercialisation. It also considers limits to change, such as the political environment, problems of capital, the role of the financial system and contemporary economic theory. The pamphlet provides a new perspective from which the political, social, constitutional and ecclesiastical changes of the century must be viewed.