Suppose Einstein had not existed. How, in the early twentieth century, might our understanding of space–timeSpace-Time physics have developed? This paper proposes a reconstruction of history as it could have evolved, drawing on attested pre-Einsteinian works, and some little known post-Einsteinian ones, as well as introducing a few imaginary characters. The virtual rise of Minkowskian chronogeometryChronogeometry will be reviewed, focusing on: the discoveryDiscovery of the inertiaInertia of energy and the subsequent construction of velocity-dependent formulas for energy and momentumMomentum by Von Dida (1909) and Hunepierre (1909), and the application of the Erlangen program to the construction of possible space–timeSpace-Time structures and classification of chronogeometrical groups, from von Ignatowsky (1910, 1911), Franck and Rothe (1911, 1912) to Blondeville and Prostov. Some secondary sources will also be discussed Zweistein (1905). Finally, the relevance of such an approach, on educational, epistemological and cultural grounds, will be highlighted and put in perspective within the ongoing debate about the contingencyContingency vs inevitability of scienceScience history.