After the revolution in 1848 Franz Joseph I. became emperor of the Austrian Empire, which was founded in 1806 after the liquidation of the Holy Roman Empire. He ruled till 1916. Vienna became a center of arts, culture and architecture. The city grew because the suburbs became part of the city. After 1858 the walls of the city were destroyed and the Ringstraße replaced them. Along that street houses of the rich citizens were built, as were public buildings like the city hall and the Burg theatre. The industrialisation started at the beginning of the century and made more people live there. In 1870, Vienna had one million people, and in 1910, two million people. With the creation of a large working class and poverty in Vienna the Labour Party (Sozialdemokratische Arbeiterpartei) became stronger.