The navigator Carl Weyprecht conducted an extensive correspondence throughout his life, beginning already in 1856. The present volume publishes for the first time more than 200 letters to his parents, his correspondence with Count Hans Wilczek, patron of several Austria-Hungarian polar expeditions, and his correspondence with the geographer August Petermann. Together with other letters, particularly to his personal friend Heinrich von Littrow, this has resulted in a collection of documents that reveal a fascinating personality. The letters to his parents provide insights into everyday life as well as the problems and attitudes of the Austrian navy in the 1850s and 1860s. Together with August Petermann, he planned and discussed the polar expeditions of the years 1868 to 1871, and Count Wilczek became a paternal friend and patron. In December 1874 they had the idea of installing simultaneously operating circumpolar stations in the Arctic and Antarctic. In 1875 the plans were complete and Weyprecht wrote letters to promote them, receiving words of encouragement from all sides. Receiving financial support initially only from Count Wilczek, he succeeded in realizing his idea of the "International Polar Year." However, the project nearly fell through because of several set-backs. When it was finally successfully realized in 1882/1883, Carl Weyprecht had already prematurely passed away. This edition of his letters is accompanied by introductory articles about Carl Weyprecht and Count Hans Wilczek, a historical summary of the realization of Weyprecht's idea of an "International Polar Year," as well as a concluding chapter containing short biographies of the most important personalities mentioned in his letters.