The chapter traces the historical development of banking and finance in Ireland. The financial system has historically been characterized by domestic economic weakness alongside significant activity by foreign firms, with state agencies filling the gap. Overall, the sector has been vulnerable to internationalization, and booms and risks. The chapter explores how, through the 1990s, it transformed from a sleepy backwater to one of the most financialized systems in Europe. This was driven by the transnational integration of the Irish banking system, linked to a shift towards market-based banking. In the 2000s, new technologies formed a disastrous combination with domestic conditions, ultimately leading to the banking crisis and the loading of banking debts onto the public purse. Finally, the chapter examines the politics of the Irish bailout. This was not simply a matter of domestic politics, nor of the bargaining power of banks, but involved EU interstate politics.