​​Franz Oppenhoff was one of the central figures in the city's history during the transition from Nazi dictatorship to post-war period. Today, one of the most beautiful streets in Aachen bears the name "Oppenhoff-Allee", although it's likely only a few of the city's inhabitants know its namesake.

Oppenhoff was a lawyer who was active in Aachen from 1933 and, among other things, defended Catholic clergymen against the regime's attacks. He gained his vulnerable role as Mayor of Aachen immediately after the American invasion. The Bishop of Aachen, Johannes Joseph van der Velden, proposed him to the US occupation forces as the new head of the city. Oppenhoff was sworn in as early as 31 October 1944 and subsequently endeavoured to act as an intermediary between the new rulers and the German population. One of the central areas of conflict was his demand that the city's streets be opened for the delivery of the food that was urgently needed.

Samuel Padover, an American history professor and member of the Department of Pyschological Warfare within the US Army, became Oppenhoff's greatest rival. Padover massively attacked Oppenhoff and the city administration, because for him the city authority seemed too conservative. The debates about this, known as the "Aachen scandal", even reached the US press.

​Regardless of this, because of his cooperation with the American occupiers, Oppenhoff was hated by the Nazis. In the evening hours of 25 March 1945, a Werewolf-Kommando squad visited Oppenhoff's unguarded private home and murdered him there. The first city leader of the post-war period was buried at the East Cemetery. To this day, he is remembered on Oppenhoff-Allee, where a monument also commemorates his fate.​