‘Synthesis’ considers how the shape and scale of chemistry has been transformed since the start of the 20th century. A series of world wars; a shift from coal to oil as the feedstock for the chemical industry; the introduction of physical instrumentation, quantum mechanics, and electronic theories; the organization of academia and industry to create Big Science as opposed to the more individualized research of previous centuries; a shift from European dominance of the subject to the US and then Russia, Japan, and China; and more women joining the profession have all been important. Underlying these changes was the theme of synthesis of natural chemicals and the creation of artificial materials.