Baedeker to have three of his four sons − Hans, Ernst and Dietrich − beside him in the firm, as editors and writers. Karl Baedeker III, the fourth son, entered academia and rose to become a professor of physics at the University of Jena. He was killed in action at the Battle of Liège in August 1914. It was his son Karl Friedrich who revived Verlag Karl Baedeker after the Second World War. During his reign, which lasted over 50 years, Fritz produced 73 new "Baedekers", as they came to be known universally. The Baedeker travel guides became so popular that
Maximilian Karl, 6th Prince of Thurn and Taxis Karl and Mathilde Sophie had twelve children: In 1843, Maximilian Karl and his family moved to the newly constructed princely castle of the Thurn and Taxis family in Donaustauf, which was completed in the same year as the nearby Walhalla. The castle Donaustauf was completely destroyed during a blaze on 4 March 1880. In 1827, Maximilian Karl was his father's successor as head of the private Thurn-und-Taxis-Post which had its headquarters in Frankfurt am Main. With the annexation of the Free City of Frankfurt by the Kingdom of Prussia in 1866 and the forced sale of Thurn-und-Taxis-Post for three million