The world of money and finance has been transformed almost beyond recognition in the past thirty years. As late as the 1970s, banks and other financial institutions were highly regulated, with little competition, and in many countries the movement of capital across international boundaries was tightly controlled. Many of these restrictions were swept away in a series of reforms, inaugurating a period of structural change and innovation. Nowhere was this more evident than in the City of London, one of the centres of the world financial system, where the ‘Big Bang’ of 27 October 1986, a set of reforms that changed overnight the regulations governing the way financial markets were organized, initiated enormous structural transformations, such as allowing banks to acquire stockbroking and market-making businesses. At the same time, new trading floors and the exploitation of modern technology transformed the way in which business was conducted. London became, in the view of many, the centre of the world's capital markets. But it was a London from which the old firms had disappeared and which was now dominated by American firms, with names like Goldman Sachs, Salomon Brothers, Morgan Stanley, Merrill Lynch, J. P. Morgan, and Lehman Brothers. London was becoming part of an international financial world in which geography was, for the most part, irrelevant.

It was not just the way financial institutions were organized that was transformed: the period starting in the early 1970s was one of ferocious financial innovation, with the creation of new financial assets too numerous to mention.