Cornelius Cruys Cornelius Cruys ( ) ( 1655 – 1727 ) was a Dutch Vice Admiral of the Imperial Russian Navy and the first commander of the Russian Baltic Fleet . He was born in Norway . Early life and career . He was born as Niels Olsen ( Olufsen ) in the city of Stavanger in Norway in 1655 and was half Norwegian and half Dutch . It is uncertain when the Norwegian Niels Olsen ( in Dutch ` Cornelis Roelofsz ' ) emigrated to the Dutch Republic and changed his name to Cornelis Cruys ( " Kornelius Krøys " or " Cornelis Cruijs " ) . However , according to several municipal sources , Cruys lived in Amsterdam for at least eighteen years before he joined the Russian Navy . The first known record about Cruys was produced by the local administration of Amsterdam in 1681 . That year he married the nineteen - year - old Catharina Voogt . She was born in Amsterdam and was the daughter of Claas Pieterszoon Voogt , a Dutch captain of a merchantman , and Jannetje Jans . In the civil registration of his marriage , Cruys was called a sailor from Amsterdam , 24 years old , an orphan . In December of that year , about seven months after his marriage , Cruys was officially registered as a citizen or " poorter " of Amsterdam . In 1680 Cruys became the captain of a Dutch merchantman . Until 1696 he sailed to Portugal , Spain and the Caribbean . In July 1696 he joined the Dutch Navy . He was appointed " onder - equipagemeester " at the naval dockyard of the Amsterdam Admiralty . In less than two years he would leave Holland for the Russian Navy . Service in Russia . In 1697 , Russian Tsar Peter the Great travelled incognito with a large Russian delegation - the so - called Grand Embassy . He visited the Netherlands to study the latest inventions , especially in shipbuilding . Thanks to the mediation of Nicolaas Witsen , mayor of Amsterdam and expert on Russia " par excellence " , the tsar was given the opportunity to gain practical experience in the largest private shipyard in the world , belonging to the Dutch East India Company in Amsterdam , for a period of four months . The tsar helped with the construction of an Eastindiaman especially laid down for him : Peter and Paul . During his stay in the Netherlands the tsar engaged , with the help of Russian and Dutch assistants , many skilled workers such as builders of locks , fortresses , shipwrights and seamen . They had to help him with his modernization of Russia . The best - known sailor who made the journey from the Netherlands to Russia was Cornelis Cruys . Cruys accepted the tsar ' s generous offer to enter into his service as vice - admiral . He emigrated to Russia in 1698 and became the tsar ' s most important adviser in maritime affairs . Cruys performed well in Russia and came be regarded as the architect of the Russian Navy . After his return to Russia the tsar put his Azov Flotilla under the command of admiral Fyodor Golovin , a Russian nobleman who was the successor of the Swiss Franz Lefort . Golovin was assisted by vice - admiral Cruys and rear - admiral Jan van Rees . Cruys became the first " Russian " mayor of Taganrog 1698 - 1702 . In 1711 he made the first maps of Azov Sea and Don River . He was commander of the Russian Baltic Fleet from 1705 and masterminded the construction of Kronstadt fortress , which was essential in the Great Northern War against Sweden and many years later against the German Kriegsmarine during World War II . Cruys worked for the tsar for more than 25 years and reached the highest Russian naval rank of admiral in 1721 . He died in Saint Petersburg in 1727 , two years after the death of his master Peter the Great . The historic Kotomin House , erected after Cruys ' death , is located in the place where his house once stood .