At the end of the 16th-beginning of the 17th century Sweden makes its expansion to the East. In 1610-1611 the Russians and Karelians heroically defended the town of Korela from Swedish troops. They could seized the town only after 6 month siege.
Under conditions of Stolbovsky treaty of 1617 Russia ceded Karelian istmouth to Sweden and as a result
a lot of Karelians moved to the territory of Russian state. The migrants settled both in boundary and central districts of Russia. The largest part of them (25-30 thousand) settled down on the territory of Tverskoy land
and it gave life to the ethnic group of the so called Tversky Karelians.
With the loss of Karelian istmouth the fortress-town Olonets built in 1649 became an administrative and trade center of Karelia. In the 17th century iron
work crafts were very popular among peasants, the goods being brought to Tverskaya fair. Shungskaya fair in Zaonezhye became more important as it served as a link between Karelian Pomorye and Southern Karelia.
Under Peter the First power the set of mining plants was built on the territory of Karelia. It was called Olonetsky mining plants
(Petrovsky, Povenetsky, Alexeevsky, Konchesersky). These plants played a very important role at the time of
Northern war. They supplied the Russian Army and Navy with cannons, cannon balls, pistols, swards and other armament. Petrovsky plant gave life to Petrovsky settlement (1703), then grown into the town of Petrozavodsk. Under Nishtadtsky peaceful treaty of 1721 the Karelian istmouth was given back to Russia.
From the history of Karelia | the most important historical dates and events