Baedeker "baedekering" became an English-language term for the purpose of traveling in a country to write a travel guide or travelogue about it. Fritz Baedeker became the most successful travel guide publisher of all time and turned the publishing house into the most famous and reputable publisher of travel guides in the world. In 1909, Leipzig University conferred an honorary Ph.D. (a rare honour at the time) on him at its 500th anniversary convocation. This era in its history was brought to an end by the outbreak of World War I, after which the house of Baedeker went into decline, the
Baedeker he published his first offering—10,000 copies of "Schleswig-Holstein". This was printed in Glückstadt near Hamburg and contained some advertising to balance the books, as did some of his other contemperaneous titles. Allen & Unwin, the London publisher, once again helped the Baedeker firm with another loan and he published more city and regional guides in the years that followed. In 1951, Karl Friedrich and Oskar Steinheil, a pre-war Baedeker editor, signed an agreement with Shell AG, the subsidiary of Royal Dutch Shell, and Kurt Mair (1902–1957), the German printer and publisher based in Stuttgart, to produce a series of motoring