Rainer Candidus Barzel (June 20, 1924 – August 26, 2006) was a German politician of the CDU.Born in Braunsberg, East Prussia (present-day Braniewo, Poland), Barzel served as Chairman of the CDU from 1971 and 1973 and ran as the CDU's candidate for Chancellor of Germany in the 1972 federal elections, losing to Willy Brandt's SPD.The 1972 election is commonly regarded as an indirect referendum on Chancellor Brandt's Ostpolitik (eastern policy), which called for normalized relations with the GDR and the USSR, and which Barzel vehemently opposed.