This book is essentially the third volume on the history of British Petroleum (BP) from 1901to 1975, which the author has tried to present on its own, to be read with or without reference tothe previous two volumes. It deals with three phases of BP's developments during1950–75, starting with the 1950–54 period of Iranian oil-nationalization crisis, the1955–70 phase of growth and internationalization, and finally the 1974–75 takeoverby the Organization of Petroleum Exporting Countries (OPEC). The author has been BP's“official historian” for years, and the company's “HistoryCommittee” has approved the present study.