Oswald Mathias Ungers (July 12, 1926 September 30, 2007) was a German architect and architectural theorist, known for his rationalist designs and the use of cubic forms. Among his notable projects are museums in Frankfurt, Hamburg and Cologne. Oswald Mathias Ungers was born in Kaisersesch in the Eifel region. From 1947 to 1950 he studied architecture at the University of Karlsruhe under Egon Eiermann. He set up an architectural practice in Cologne in 1950, and opened offices in Berlin in 1964, Frankfurt in 1974 and Karlsruhe in 1983.