Nyenskans, a Swedish fortress, was founded at the mouth of the Neva River in 1611, in a land then called Ingermanland. A small town called "Nyen" grew up around it.
Peter the Great was interested in seafaring and maritime affairs, and he aimed to have Russia gain an ability to take to the seas, so it could trade with other maritime nations. In order to do so, he needed a better seaport than Arkhangelsk, which was on the White Sea to the north.
The Bronze Horseman, monument to Peter the Great
On May 12 [O.S. 1] 1703, during the Great Northern War, Peter the Great captured Nyenskans, and soon set about replacing that fortress. On May 27 [O.S. 16] 1703, closer to the estuary (5 km/3 miles inland from the gulf), on Zayachy (Hare) Island, he laid down the Peter and Paul Fortress, which became the first brick and stone building of the new city.
The city was built by conscripted peasants from all over Russia; a number of Swedish prisoners of war were also involved in some years under the supervision of Alexander Menshikov. Tens of thousands of serfs died building the city. Later the city became the centre of Saint Petersburg Governorate. Peter moved the capital from Moscow to Saint Petersburg in 1712, 9 years before the Treaty of Nystad of 1721 ended the war, although he was already referring to Saint Petersburg as the capital (or seat of government) as early as 1704.
During the first few years of its existence the city grew spontaneously around Trinity Square on the right bank of the Neva, near the Peter and Paul Fortress. However, Saint Petersburg soon started to develop according to a plan. By 1716 Domenico Trezzini had elaborated a project whereby the city centre would be located on Vasilyevsky Island and shaped by a rectangular grid of canals. The project was not completed, but is still evident in the layout of the streets. In 1716 Jean-Baptiste Alexandre Le Blond was appointed chief architect of Saint Petersburg by Peter the Great
