Viennese painter, who was the founder of the Vienna Secession, the Austrian art nouveau movement. His early work, consisting principally of large murals for theaters, was painted in an unremarkable naturalistic style. After 1898, his work moved toward greater innovation and imagination, taking on a more decorative, symbolic aspect. Klimt's best-known works are his later portraits with their flat, unshadowed surfaces, translucent, mosaic colors and forms, and sinuous, curling background lines and patterns. Among his most admired works is the series of mosaic murals.