Foundation of Petrozavodsk city is closely linked with the name of the Russian emperor Peter the Great. In 1703, the same year with establishment of St. Petersburg, Petrovsky ore mining and cannon factory was laid down in the mouth of Lososinka river, on the shores of Onega lake. Its main purpose was processing local lake and marsh ore, cannon foundry, producing rifles and cold steel. The Northern war was at its height, Russia was fighting for an access to the Baltic, and in these circumstances the factory's proximity to the seat of war and opportunities of the ready weapons' transporting across the Onega lake contributed to the production's rise and growth of Petrovsky settlement.
Having reached the peak of its development by the 20ies of 18th century, after the end of the Northern war the Petrovsky factory cuts down cannon production, the factory settlement grows empty and gradually falls into decay. However, already in the middle of the 18th century Russia's active policy at its outer borders, both northern (against Sweden) and southern (against Ottoman Turkey) again demanded build-up of weapons' production. A new cannon factory named Alexandrovsky, appears.
Production and population growth led to the decree by Ekaterina II, dated March 21st, 1777, which granted the settlement the status of the town, now named Petrozavodsk.
Starting 1781 Petrozavodsk becomes a center of Olonets province, after 1828, when a separate Olonets eparchy was established and a bishop's chair was set up in Petrozavodsk, the city grows into an important regional church center.
Revival of the city's economy in the second half of the 19th century was based on the growth of private industrial enterprises - sawmills, matches factory, brickworks. Economy growth resulted in the rise of population, the city got its own educational and medical institutions, libraries, museums. In 1861 a regular cargo-and-passengers' connection to St. Petersburg was opened.
The city's public life in 19th - early 20th century was strongly influenced by the presence of political exiles, forced out of St. Petersburg and Moscow by the ruling tsar family. First exiles were representatives of the Russian nobility opposed to the existing regime. By the end of the 19th century with the growth of "raznochinetz movement" the political exile community was under the influence of educated intellectual people not belonging to the gentry. In 1870-ies the amount of exiles numbered 100-200 people. Young people, holding to the liberal values, often were disturbing the public peace. On the other hand, exiles were positively influencing the society, bringing to the provincial city the most advanced views, ideas, intellectual trends.
After the period of Intervention and Civil war, Petrozavodsk became the capital of Karelian Labor Commune, which in 1923 was transformed into Karelian ASSR (Autonomous Soviet Socialist Republic).
Petrozavodsk did not escape the ordeals of the Great Patriotic war years. From October 1941 to June 1994 the city was occupied by the Finnish troops and got almost completely destroyed.
50-80ies of the 20th century is the period of establishing the contemporary image of the city, time of intense industrial engineering and house-building.
Today Petrozavodsk is an important industrial and infrastructure center of the Russian North-West, educational center, city of science and culture.