Edith Penrose was a creative thinker, a distinguished economist, and an inspirational teacher who profoundly challenged the prevailing orthodoxy in several fields, including micro-economics, business studies, and development economics. Her major contribution to the field of economics was The Theory of the Growth of the Firm (1959), now regarded as a classic that has ‘inspired thinking in strategy, entrepreneurship, knowledge creation, and innovation’. Edith Penrose’s approach to explaining the nature of the firm, her fundamental insights, and the concepts she developed are still being applied and extended to new fields of enquiry. She has had a major influence on the study of the business enterprise and, some argue, the economy itself. She had a distinguished academic and public service career and wrote over 100 books and articles, many of which are devoted to the understanding of the interface between the strategies and activities of multinational enterprises, including the oil industry, and the nation states—particularly the developing countries—in which they operated. This is the first biography of Edith Penrose drawing on unpublished diaries and letters, the personal memories of her family, friends, and colleagues, and describes her eventful life, her extensive output, and influence. The book tells her personal and professional story, weaving through the extraordinary upheavals of the twentieth century in which she played a part. The book builds a picture of a vital, energetic woman who lived life to the full, defied convention, made an impression on all who met her, and left a significant intellectual legacy.