Speaking at the annual Conservative party conference in 2016, Theresa May, the former British prime minister, remarked: “If you believe you are a citizen of the world, you are a citizen of nowhere.” One wonders what Count Richard Coudenhove-Kalergi would have made of that.

Born in Tokyo, raised at his family’s castle in Bohemia under the Austro-Hungarian empire, the count was 26 years old when he wrote in 1921: “As a result of my parentage — my father was a European from the Flemish, Greek, Russian, Polish, German and Norwegian nobility, my mother was a middle-class Japanese woman — I have no exclusive sense of belonging to any nationality, race or class.”

Coudenhove-Kalergi was an author, part-time intellectual and political campaigner whose faith in European unification remained undimmed from the aftermath of the first world war until his death in 1972. Although he never ran for or held government office, he is still held in high esteem in parts of continental Europe for his unflagging devotion to the cause.

As Martyn Bond writes in his sympathetic but not uncritical biography, Hitler’s Cosmopolitan Bastard, it is striking how many of the count’s ideas — a single currency, customs union, charter of human rights, common anthem and much more — have come to fruition as Europe’s integration has proceeded, by fits and starts, from 1950 to the present day. No less striking is that the count’s name is almost unknown today in the English-speaking world.

Bond, a former EU civil servant and BBC foreign correspondent, points out that this was by no means true in Coudenhove-Kalergi’s lifetime. Winston Churchill paid tribute to the count’s work in a 1946 speech at the University of Zurich made famous by the ringing phrase: “We must build a kind of United States of Europe.” Yet whatever Churchill meant by these words, neither he nor other British politicians after 1945 had in mind the full-blown union that the count advocated.

Coudenhove-Kalergi published Pan-Europa, his best-known book, in 1923 and launched his Pan-Europa Union one year later. It fell far short of growing into a mass political movement, but the count had a talent for attracting interest from political leaders, notably the French statesman Aristide Briand and the Austrian chancellor Ignaz Seipel, who offered him rent-free use of offices in the Hofburg, the seat of Austria’s government.

Still, the count’s reluctance to go into traditional politics limited his influence. Nationalists scorned his ideas, and pragmatists doubted their practicality. Politische Wochenschrift, a rightwing Berlin newspaper, derided him as “Narcissus leaning over the European pool and observing his own reflection”. Sir William Tyrrell, permanent under-secretary at the UK Foreign Office, called him “a thoroughly impractical theorist”.

Adolf Hitler despised the count, denouncing him in the late 1920s as a “cosmopolitan bastard” — hence the title of Bond’s book.

Bond rightly draws attention to the count’s occasional errors of judgment. He persisted in seeing Italian dictator Benito Mussolini as a potential ally in unifying Europe. He had little enthusiasm for mass democracy, musing that the best form of government might be, in Bond’s words, “under the supervision of a select body of informed intellectuals, an aristocracy of the spirit”.

Coudenhove-Kalergi once suggested that it did not matter if a regime was fascist or democratic, so long as it pursued peace and European unity. He came late to the recognition that the existential choice in the interwar era was between democracy and totalitarianism.

The count also had some strange ideas about the impact on the world of decolonisation. To Charles de Gaulle, the French president, he wrote in 1962 that the UN, filling up at the time with newly independent developing countries, “represents for Europe, indeed for the whole of the white race, the worst danger since the days of Genghis Khan”.

The greatest progress in postwar European integration was made by men such as Jean Monnet, the French statesman who kept his distance from the count and did not deign to mention him in his 1976 memoirs. Yet Coudenhove-Kalergi left a lasting legacy of ideals and imagination. Bond’s biography, the first English-language study of the count, is a fitting tribute to his memory.

Hitler’s Cosmopolitan Bastard: Count Richard Coudenhove-Kalergi and His Vision of Europe by Martyn Bond McGill-Queen’s University Press, £24.99, 464 pages

Tony Barber is the FT’s Europe commentator

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