Ludwig Wilhelm Erhard was a German politician affiliated with the CDU, and chancellor of West Germany from 1963 until 1966. He is known for leading the West German postwar economic reforms and economic recovery in his role as Minister of Economic Affairs under Chancellor Konrad Adenauer from 1949 to 1963. During that period he promoted the concept of the social market economy, on which Germany's economic policy in the 21st century continues to be based. In his tenure as Chancellor, however, Erhard lacked support from Adenauer, who remained chairman of the party until 1966, and failed to win the public's confidence in his handling of a budget deficit and his direction of foreign policy. His popularity waned, and he resigned his chancellorship on 30 November 1966.