Peter returned to Moscow in November 1695 and began building a large navy. He launched about thirty ships against the Ottomans in 1696, capturing Azov in July of that Year. On 12 September 1698, Peter officially founded the first Russian Navy base, Taganrog which became the Russian Black Sea Fleet. During the Great Northern War of 1700–1721, the Russians built the Baltic Fleet. The construction of the oared fleet (galley fleet) took place in 1702–1704 at several shipyards (estuaries of the rivers Syas, Luga and Olonka). In order to defend the conquered coastline and attack enemy's maritime communications in the Baltic Sea, the Russians created a sailing fleet from ships built in Russia and others imported from abroad.