"Most economic growth theorists see human capital input as a key factor in long-term economic development. Little is known, however, about the role of human capital in the historical process of industrialization of Western Europe. Recent empirical attempts to identify human capital in the past face the problem that human capital is difficult to quantify, particularly before public schools become widespread. Existing measures of human capital in preindustrial Europe (notably literacy rates, numeracy rates and number of apprenticeships) suffer from the drawbacks that they either identify only very basic skills (as in the case of numeracy and literacy) or that they cover only a modest and biased fraction of the population (as in the case of apprenticeships). More importantly, all of them are subject to the criticism that not all the skills acquired by workers were necessarily used in their productive activities.The present study offers a new approach to measuring human capital used in productive activities based on historical occupational titles. The methodology relies on a well-established classification of historical occupations known as the HISCO system. The HISCO system categorizes tens of thousands of occupational titles from countries and languages all around the world from the sixteenth to the twentieth century. In combination with the HISCLASS system, which maps occupational titles into skill-levels used in order to conduct the work described by the occupational title, it is possible to subdivide occupations according to four degrees of working competences depending on the level of ability required to perform the work, namely higher-skilled, medium-skilled, lower-skilled and unskilled occupations. By assigning a score to each of the four skill-levels, it is then possible to compute and study the evolution of the labour force’s skills used in productive activities across time, space and social groups in England and the rest of Western Europe before and during"