A 1917 agreement with French publisher Hachette allowed co-publication in English and French of guidebooks under the names Blue Guides and Guides Bleus, respectively. Hachette’s existing Guides Joannes had blue covers, while Baedeker’s guides had red covers. The first Blue Guide, Blue Guide London and its Environs, was published in 1918. Two years later, Hachette published Guide Bleu Londres et ses Environs. The Hachette relationship with the Blue Guides ended in 1933.
