For most of the 20th century ICI was Britain’s leading industrial company. It was formed in 1926 through the merger of four chemical companies – Brunner Mond, Nobel Explosives, United Alkali and British Dyestuffs. The company declared that it would champion “the responsible application of chemistry and related sciences” to business. The chemical markets of the world were shared, more co-operatively than competitively, between ICI and its rivals DuPont and IG Farben.

After the second world war the ICI board shrewdly perceived that the new frontier of chemistry was pharmaceuticals. In those days ICI was one of the few British manufacturing companies active in recruiting graduates, and the pharmaceutical division hired a team of able young scientists. Among them was James Black, a physiologist from the University of Glasgow. Despite the quality of its research chemists, ICI’s pharmaceutical division lost money for almost two decades. It is hard to imagine a listed company, or its shareholders, tolerating a similar financial performance today.

In the 1960s Black discovered beta-blockers, the first effective drug for treating high blood pressure. Other products followed, and the pharmaceutical became ICI’s fastest-growing source of profit. Black was feted (if not especially well paid) by the company. But his interest was in research, not management or marketing. Believing that the science underlying beta-blockers had other uses, he left ICI for the greater freedom offered by Smith Kline.