In the spring of 1951, Dutch shipping and trade representatives sailed up the Rhine to Basel.

On this promotional tour, Amsterdam's mayor d'Ailly stopped off in the Hessian state capital on April 6. After being greeted by the Kalle-AG works choir at the jetty in Biebrich, the delegation toured the chemical factory. Lord Mayor Redlhammer and representatives of the Hessian state government then welcomed the Dutch to the town hall.

The politicians recalled the good relations between Germany and the Netherlands. They were confident that in future the Rhine would develop from a mere transport route into a symbol that unites people. To commemorate the visit, Redlhammer presented his counterpart with a Meissen porcelain plate bearing the Wiesbaden coat of arms.

D'Ailly thanked him for the warm welcome and then signed the city's Golden Book.