The oldest European unification movement is the Paneuropean Union, founded in 1923 with the publishment of Richard von Coudenhove-Kalergi's book Paneuropa, who also became its first president (1926–1972), followed by Otto von Habsburg (1973–2004) and Alain Terrenoire (from 2004). This movement initiated and supported the "integration process" pursued after World War II, which eventually led to the formation of the European Union. Notable "Paneuropeans" include Konrad Adenauer, Robert Schuman and Alcide De Gasperi.