The development of koch began in the 11th century, when the White Sea shores began to be settled. This type of ship was in wide use during the heyday of Russian polar navigation in the 15th and 16th centuries. There is documentary proof that in those days the private Russian civil fleet in the Arctic seas numbered up to 7,400 small ships in a single year. In the 17th century, kochs were widely used on Siberian rivers during the Russian exploration and conquest of Siberia and the Far East. In 1715, during the Great Northern War, the Russian Arctic shipbuilding and navigation were undermined by the "ukase" (decree) of Tsar Peter the Great. According to the ukase, only "novomanerniye" ("new-mannered") vessels could be built, that is the civil ships, which could also be used for military purposes. The koch with its special anti-icebound features did not suit this aim.