He was born in Antwerp, and began his education at the Koninklijk Atheneum (E: Royal Atheneum) of Antwerp, where he was influenced by the Flemish writer and liberal politician Jan van Beers, and he obtained a law degree at the Free University of Brussels (now split into the Université Libre de Bruxelles and the Vrije Universiteit Brussel).

As the president of the Conférence du Jeune Barreau (Young Lawyers' Conference) and as a member of the Vlaamse Conferentie der Balie (Flemish Bar Association), he wanted to promote the use of Dutch in court (which was in French in those days).

Since then he fought on the side of the Roman catholic Frans Van Cauwelaert and the socialist Camille Huysmans (together they were called the three crowing cocks) for the usage of Dutch at the University of Ghent.

During the German occupation of Belgium in World War I, Franck (under the influence of the Belgian king and the government) acted as the president of a Intercommunale Commissie van Notabelen, the actual head of Antwerp and the neighbouring municipalities.

After the war he became Minister of Colonies (1918–1924), and on 27 September 1926, he succeeded Fernand Hautain as governor of the National Bank of Belgium and together with Paul van Zeeland, he led this institute for many years in a dynamic but autocratic and self-opinioned way.