‘The unpredictability of biography,’ writes Timothy Snyder in On Freedom, ‘flows into the unpredictability of history.’ This is self-evidently true of leaders who, like William Henry Gates III, also known as Bill Gates, the co-founder of Microsoft, initiate the kinds of change that are destined to be viewed as history. Their lives, like all of ours, are amply shaped by contingency and event, the ‘what if’ moments and decisive decisions, both their own and others’. The mystique of what might never have been, or might have been otherwise, is powerful. Even though there are many alternatives and competitors, it is hard to imagine personal computing evolving as it did without the ubiquitous Microsoft products that have shaped the world. Consumer technologies such as these, which were also an early form of AI, have become all but invisible. Gratifyingly, the Microsoft co-founder and former CEO’s first autobiographical instalment, Source Code, is liberally sprinkled with fork-in-the-road moments and tensions. It is a hero’s journey narrative, blending memoir with personal case studies in business leadership and strategy. The book begins with Gates’s early childhood and ends in 1978. The author foreshadows a further two volumes.