How do I prevent the annexation of the Novgorod Republic?

Question

The Novgorod Republic existed in northern Russia between 1136 and 1478. It was the easternmost point in the Hanseatic League, the north-western terminal of the Silk Road, and by all accounts immensely prosperous. It was a democracy with a very permissive suffrage (even lower classes could vote, though serfs could not) and high level of literacy.

Novgorod was too far north to suffer militarily from the Mongols, but it didn't help them much:

• They still had to pay tribute to the Mongols
• They were a target for Catholic crusaders from Sweden and the Baltics
• They were engaged in wars with the other Russian principalities, most importantly Muscovy (Moscow).

Novgorod had some success playing its enemies against one another, but Muscovy eventually grew too powerful. When Novgorod tried to ally with Poland-Lithuania, Moscow's ruler Ivan III declared war, defeated Novgorod's army, and crushed any hope of independence.

What is the smallest change that could avoid this outcome for as long as possible, without simply supplicating Novgorod to another overlord (Sweden, Poland-Lithuania, etc)?

Answer 1

I would recommend saving Tver. Tver and Muscovy were significant regional rivals until the city revolted against Tatar rule and the Tatars sacked the city, from which it never recovered. If the Tatars were weakened earlier, they likely would have left Tver alone and faded more rapidly. Probably the best way to do this is simply eliminate Oz Beg. This would weaken the Golden Horde significantly, considering his prominence, eliminate his favor of Moscow, and save Tver.

Thus, entering the 15th century we could still have a delicate balance of power between a Muscovite-Novgorod alliance and a more powerful state of Tver that gained more Golden Horde lands. As the 15th century arose, ally Novgorod with Lithuania- but this time, the Muscovites cannot take action because of their need to fend off Tver, while meanwhile the Lithuanian-Novgorod alliance defeats the Teutonic Order at the Battle of Grunwald leaving Novgorod in a strong position, probably with more Baltic lands.

After that it easily becomes more hazy, but modifying history to eliminate Oz Beg and still allying Novgorod with Poland-Lithuania is probably going to at least put them in the position as a dominant state in Russia at the turn of the 15th century.