Gräfe und Unzer (Königsberg) - publishing house was founded in 1722 by Christoph Gottfried Eckart, initially operating as the “Haus der Bücher” bookshop on Junkerstraße. From 1832 it worked under the name Gräfe und Unzer (the name was formed from the surnames of the then co-owners, who were spouses), publishing scientific works, textbooks, and the famous “Ostpreußenkalender”. In 1927 it became the largest assortment book company in Europe.