Karl Ehn was a Viennese

Vienna

Vienna is the capital and largest city of the Republic of Austria and one of the nine states of Austria. Vienna is Austria's primary city, with a population of about 1.723 million , and is by far the largest city in Austria, as well as its cultural, economic, and political centre...

 architect

Architect

An architect is a person trained in the planning, design and oversight of the construction of buildings. To practice architecture means to offer or render services in connection with the design and construction of a building, or group of buildings and the space within the site surrounding the...

 and city planner.

Among other structures, Ehn designed the colossal Karl-Marx-Hof

Karl-Marx-Hof

Karl Marx-Hof is one of the best-known Gemeindebauten in Vienna, situated in Heiligenstadt, a neighbourhood of the 19th district of Vienna, Döbling.-Development:...

, the largest and best example of innovative public housing built during the Red Vienna

Red Vienna

Red Vienna was the nickname of the capital of Austria between 1918 and 1934, when the Social Democrats had the majority and the city was democratically governed for the first time.-Social situation after World War I:...

 movement. Ehn worked as technical director for the City of Vienna and was a student of Otto Wagner

Otto Wagner

Otto Koloman Wagner was an Austrian architect and urban planner, known for his lasting impact on the appearance of his home town Vienna, to which he contributed many landmarks.-Life:...

. According to Joseph Rykwert

Joseph Rykwert

Joseph Rykwert is Paul Philippe Cret Professor of Architecture Emeritus at the University of Pennsylvania, and is widely regarded as the most important architectural historian and critic of his generation. He has spent most of his working life in the United Kingdom and America...

, after the Anschluss

Anschluss

The Anschluss , also known as the ', was the occupation and annexation of Austria into Nazi Germany in 1938....

 in 1938 Ehn continued to serve the city under the Nazis.