From the 1880s on Italy underwent gradual but significant urbanization. The causes lay principally in population growth, the agrarian crisis brought on by the ‘Great Depression’, and the first phase of industrialization. In 1871 15.3 per cent of Italy’s population lived in urban centres with more than 20,000 inhabitants. By 1921 this had risen to 33.3 per cent and ten years later to 35.1 per cent. In the years between 1902 and 1911 Northern Italy urbanized faster than it was to do until the massive economic expansion of the 1950s. At the same time, from the end of the 1880s, GNP growth-rates rose significantly and performed best in the years 1896-1913. The average annual growth rate of the industrial sector between 1881 and 1913 is estimated at between 3.8 and 4.2 per cent. The industrial workforce numbered 2,180,627 in 1911 and rose to 4,445,757 by 1938. This synchronization of growth in population, urbanization and industrialization was not occurring in the whole of Italy but, in the years spanning the turn of the twentieth century, was certainly visible in the north west, that is the areas that were in general equivalent to the regions of Piedmont, Lombardy and Liguria. In particular, in these areas, and in their three major urbanized centres, Turin, Genoa, Milan, as they were to do in all of Italy’s cities to a lesser or greater extent, rising population and the requirements of new economic activities revealed the ancien régime character of Italian cities as well as their inadequacy in terms of housing, streets, water provision and sewage disposal, urban space and public buildings.