Pomfret, an Australian economist, uses the rallying cry of the French Revolution -- “Liberty, equality, fraternity” -- as an organizing principle for this brief but engaging history of the twentieth century, an “age of equality,” which followed an age of liberty, from 1815 to 1914, and preceded what he expects to be an age of fraternity in the twenty-first century. His argument is straightforward: the philosophical underpinnings of the United Kingdom’s Industrial Revolution emphasized the need for freedom of action from feudal restraints on commerce and, eventually, on political decision-making. Those beliefs became predominant in Europe and North America by 1914, but unfettered capitalism left too many people behind. Marxism, communism, fascism, and non-Marxist social democracy all emerged in reaction to the resulting inequality, producing the great battles of the twentieth century, both within and between countries. By 2000, fascism and communism had failed, and capitalism -- tempered by government provision of education, health care, and a social safety net -- had won. The collective challenges of the twenty-first century, such as the proliferation of nuclear weapons and climate change, call for an age of fraternity.