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 Friedrich Köppen Karl Friedrich Köppen Karl Friedrich Köppen (26 April 1808 – 26 April 1863) was a German teacher and political journalist. He was one of the Young Hegelians. Köppen was from a born in a pastor's family in Altmark. He studied theology at the University of Berlin from 1827 to 1831, but later turned to religio-critical Hegelianism. After his studies and military service in 1833, he taught at the secondary school Dorotheenstädtischer. In 1837, he met Karl Marx, with whom he developed a close friendship. In 1840 he became one of the most active associates of Arnold Ruge and published Hallischen