There was [...] a feature in the past domestic history of Russian Orthodox Christendom which may have helped Saint Petersburg to maintain itself as the capital of the Russian Empire for as long as it did. The Empire had been brought into existence through the imposition of the rule of the Grand Duchy of Muscovy upon the city-state of Novgorod between A.D. 1471 and 1479. At that date Novgorod represented one half of Russian Orthodox Christendom, and this not merely in the extent of her territory but also in the complexion and orientation of her culture. The Russian state [Rus] which had been converted to Eastern Orthodox Christianity by the cultural influence of the East Roman Empire at the close of the tenth century of the Christian Era had been founded by pagan seafarers who had made their way into Russia at her opposite extremity, from Scandinavia. Their port of entry had been Novgorod, on the River Volkhov, which the sea-going ships of the Vikings were able to ascend via the River Neva and Lake Ladoga. When the Scandinavians in their homelands were converted to Western Catholic Christianity – a conversion which was simultaneous with that of the Russians to Eastern Orthodoxy – Novgorod became a point of contact between Russia and Western Christendom, and it continued to perform this function till its subjugation by Muscovy. The heavy hand of Muscovite autocracy extinguished both Novgorod’s overseas trade with the West and the self-governing institutions that were her heritage from the pagan Viking Age and that had been favoured by the cultural effects of Novgorod’s subsequent commercial intercourse with the Hansa towns. In crushing Novgorod and what she stood for, the Muscovite empire-builder Ivan III and his successors were depriving Russian Orthodox Christendom of a valuable cultural asset, and conversely Peter the Great, in founding Saint Petersburg, was in a sense merely restoring to Russia this treasure of which his predecessors had robbed her. In purely geographical terms, Saint Petersburg was the eighteenth-century counterpart of a medieval Novgorod, taking into account the increase in the size and draught of sea-going ships that had taken place in the meantime. In cultural terms the effect of the removal of the capital of the Russian Empire to Saint Petersburg from Moscow was to create at that stage the situation which would have been created in the fourteen-eighties if at that date the political unification of Russia had been brought about through the city-state of Novgorod’s conquering the Grand Duchy of Moscow instead of through Moscow’s conquering Novgorod. In the light of this historical background, Peter the Great’s act of transferring his capital from Moscow to Saint Petersburg appears somewhat less perverse than Seleucus Nicator’s act of transferring his from a site in Babylonia [Seleucia] to Antioch.
In 882 the capital of Viking, or Varangian, Rus was moved from Novgorod on the Volkhov south to Kiev on the Dnieper. Kievan Rus, which had dissolved into a collection of principalities, fell to the Mongols circa 1240; but Novgorod, which had evolved into a largely independent republic, was spared a Mongol invasion. The Grand Duchy of Moscow did not begin to rise until the end of that century.
The Rurik dynasty, which dominated Kievan Rus (and was originally from Novgorod), also supplied the Grand Dukes of Moscow – and the first two Tsars, Ivan the Terrible (reigned 1547-84) and Feodor I (reigned 1584-98).
The Viking route from the Gulf of Finland to Lake Ilmen was via the River Neva (on which St Petersburg was built), Lake Ladoga and the River Volkhov
Kievan Rus in the eleventh century; both maps Wikimedia Commons
A Study of History, Vol VII, OUP, 1954 (footnote)