Patrick Karl O'Brien was educated at the LSE and Oxford. His Oxford doctorate, supervised by Hrothgar Habbakuk, was about fiscal and financial policy during the Revolutionary and Napoleonic Wars. His early career at the School of Oriental and African Studies was spent trying to master Arabic and to write on on the economic history of Egypt. On returning to Oxford in 1970 to take up a post as a university lecturer in economic history and fellow of St Antony's he changed course by designing a paper comparing the economic histories of Britain and France from 1789 to 1914 and writing his first book on Two Paths to the Twentieth Century for the joint degree in economics and history. In 1990 he became Director of the Institute of Historical Research at the University of London for 10 years before returning to LSE as a Centennial Professor where he helped to design and teach on a new masters programme in Global Economic History.
His publications display an unduly wide array of interests and cover, no doubt in superficial form, many of the major themes and meta-narratives that fall within the rubric recognized as economic history, including: fiscal and financial aspects of state formation, comparative economic development, science and technology, political economy, mercantilism, warfare and economic progress, landownership, etc. He has resolutely refused to be bunkered in a national history or to sacrifice breadth of view for intensity of gaze. At the end of a career that began 6 decades ago he is enjoying engagement with debate on the Great Divergence and editing a book of chapters that deal with the different outcomes that flowed for Western Europe's economies from the Revolutionary and Napoleonic Wars.