In 1900 the global average life expectancy at birth was 31 years. By 2000 it was 66. Yet, alongside unprecedented improvements in longevity and material well-being, the 20th century also saw the rise of fascism and communism and a second world war followed by a cold war. This book tells the story of the battles between economic systems that defined the last century and created today's world. The 19th century was a period of rapid economic growth, but it also brought great inequality.