One of Austria’s most influential architects, Otto Wagner (1841-1918) played a key role in modernizing urban architecture. Forming an approach described as structural rationalism, Wagner pioneered use of materials such as glass, steel, and especially aluminum. He was associated with the Viennese Succession, a group of artists and designers headed by Gustav Klimt that initiated a departure from the conservative style of the Viennese Künstlerhaus. Among Wagner’s most important buildings are the Vienna Postsparkassenamt (Postal Savings building) and the Steinhof Church.