architect and writer on art who was among the principal practitioners of the Neo-Renaissance style in Germany and Austria.

Semper studied in Munich and Paris and from 1826 to 1830 travelled in Italy and Greece, studying classical architecture. He practiced architecture in Dresden from 1834 until 1849, when, because of revolutionary activities, he was forced into exile to Paris and London. He headed the architecture department of Zürich Polytechnikum und Yorstand der Bauschule (1855–71) and between 1871 and 1876 participated in the rebuilding of Vienna. His work marks the transition away from the Neoclassicism of his friend Karl Friedrich Schinkel.

As an eclectic, Semper achieved powerful design solutions. Among his main works are the Opera House (Dresden; 1837–41, rebuilt 1878); the Zürich Polytechnikum (1858–64); and, with Karl von Hasenauer, the Burgtheater (1874–88) and the two imperial museums (1872–81), all in Vienna. In his influential writings, principally Der Stil in den technischen und tektonischen Künsten (1860–63; “Style in the Technical and Tectonic Arts”) he stressed a rational interpretation of techniques as a source of style, and recommended the use of colour in decorative arts and architecture.