The thesis is a case study into the development of child labor in the Netherlands in the nineteenth century (up to 1914), focusing on Leiden. Child labor in this study is defined as the market-orientated production of goods and services by people under the age of sixteen years. Concentrating on one town makes it possible to research the multitude of factors that are associated with the development of industrial child labor in the age of industrialization: demand (including technological renewal and rationalization), supply (living standards, demography, attitudes), the role of education, general attitudes and public discussion and the effects of legislation. Pre-industrial Leiden child labor is taken in account and a more general comparison with the Netherlands and two textiles producing regions is made. Child labor in Leiden textile industry grew in the 1840s in the wake of industrialization. The importance of child labor remained quite the same into the early 20th century. Child labor was not restricted to textiles. In many more industries child labor increased when these industrialized (after 1865) and modernized (after 1890), most notably the printing industry. In the Netherlands as a whole the picture is much the same: industrial child labor was of more importance and involved more children in 1909 than in 1849. The key factor is the unremitting demand for cheap labor, also visible in the growth of labor by young, unmarried women. The demand for better trained or educated workers was still very limited. The supply continued too. Though living standards were higher by 1900 then in the 1840s, still many working class families could hardly do without the extra income supplied by their children. Moreover, in 1910 completing lower education did not offer a real perspective of a better life to the majority of the urban working class. All the same child labor changed. Hardly any children younger than twelve years worked in industry anymore in 1900, as they did fifty years before. Now they visited schools. The ...