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
Karl Baedeker gave the name of the publisher as K. BAEDEKER, the English page gave this uniquely as CHARLES BAEDEKER. Tourists in the area, and particularly those from England on their way to Switzerland, would pass through Koblenz and buy it at his bookshop. In the preface, he wrote that "he is at all times ready to afford any information to those travellers, who do him the honour to visit his establishment"." The manual turned out to be a resounding success and ran into many editions. The inclusion of Dutch material in the first edition, also unusual at the time and emphasised