The evolution of the discipline of materials science during the second half of the twentieth century is outlined. The concept emerged in the USA, almost simultaneously in an academic metallurgy department and in an avant-garde industrial research laboratory, and its development subsequently all over the world has been a joint enterprise involving universities, industrial laboratories and government establishments. The initial impetus came unambiguously from the well established discipline of physical metallurgy, but from the 1960s onwards, the input from solid-state physicists grew very rapidly, while materials chemistry is a later addition. Of all the many subdivisions of modern materials science, polymer science has been the slowest to fit under the umbrella of the broad discipline; its concepts are very different from those familiar to metallurgists. Two fields have contributed mightily to the creation of modern materials science: One is nuclear energy and, more specifically, the study of radiation damage, the other is the huge field of electronic and opto-electronic materials in which physics, chemistry and metallurgy are seamlessly combined.