Across the globe, the Big Four accounting and audit firms - Deloitte, PricewaterhouseCoopers, Ernst & Young, and KPMG - are massively influential, earning more than $100 billion annually and employing almost a million people. In many profound ways, they have changed how we work, how we manage, how we invest and how we are governed. Stretching back centuries, their history is a fascinating story of wealth, power and luck. But today, the Big Four face an uncertain future - thanks to their push into China; their vulnerability to digital disruption and competition; and the hazards of providing traditional services in a new era of transparency. Surprisingly colorful and unquestionably authoritative, this account of the past, present and likely future of the Big Four is essential reading for anyone perplexed or fascinated by professional services, working in the industry, contemplating joining a professional services firm, or simply curious about the fate of the global economy.