[2][Note 1] His father was the director of a secondary school (Volksschule) and, as was usual among Catholics, a supporter of the Centre Party.

According to his own account, Mende shared a very trusted relationship with the commanding general of the 102nd Infantry Division, Werner von Bercken.

In this brief meeting Von Bercken encouraged Mende to openly share his pessimistic view on the outcome of the war.

[4] On his release from British custody, Mende took up the study of law and political science at Cologne University, gaining his doctorate in 1949.

As a member of parliament Mende worked tirelessly on behalf of former soldiers, those who were released after lengthy captivity (the so-called Spätheimkehrer), and those condemned as war criminals.

After the FDP increased its vote in September 1961, in the wake of the building of the Berlin Wall in August 1961, Mende urged his party not to join Adenauer in another coalition.

During his period of office West Berliners were permitted, for the first time, to cross the Wall for Christmas visits in December 1963.

Mende inaugurated agreements on road building, especially on the autobahn near Hof to facilitate better communications with West Berlin.

In opposition Mende turned his attention to his finances and worked as representative of the American international investment bank, IOS.

In protest against Brandt's new Ostpolitik and the recognition of the Oder–Neisse line Mende left the FDP[5] in 1970 and joined the Christian Democrats in opposition.