The 19th century saw a fragmentation of English architecture, as Classical forms continued in widespread use but were challenged by a series of distinctively English revivals of other styles, drawing chiefly on Gothic, Renaissance and vernacular traditions but incorporating other elements as well. This ongoing historicism was counterposed by a resumption of technical innovation, which had been largely in abeyance since the Renaissance but was now fuelled by new materials and techniques derived from the Industrial Revolution, particularly the use of iron and steel frames, and by the demand for new types of building. The rapid growth and urbanisation of the population entailed an immense amount of new domestic and commercial construction, while the same processes combined with a religious revival to bring about a resumption of widespread church building. Mechanised manufacturing, railways and public utilities required new forms of building, while the new industrial cities invested heavily in grand civic buildings and the huge expansion and diversification of educational, cultural and leisure activities likewise created new demands on architecture.