Following the clean-lined style of the Neoclassicist period was the Historicist period, lasting from about 1840-1900. Architects travelled all over the world, gathering inspiration and mixing styles. Pompous buildings with elements from many different historical styles are characteristic for Historicism.
A window from the Historicist period can resemble a window from many different eras; a Gothic window, a Baroque window or a mixture of many styles. In this period, industrialisation and new building materials such as cast iron and concrete changed the course of window production and the development of new types of windows. This is particularly true for the cast iron window; the crossbar or "Dannebrog window"; large triple-sash windows, and enormous windows in non-loadbearing façades.