Challenge: Republic of the Rus

This time my request is to try to create a TL where the Republic of Novogrod united Russia and expanded the nation keeping the Republican institutions the most possible without the transformation to an Empire.

Additional points if, as extreme challenge, Republican Russia saved Byzantine Empire and keeped it alive the most possible.
 
Hmm, Wikipedia seems to indicate the Muscovites only conquered the region after the Novogrodians sought an alliance with Poland-Lithuania against Muscovite influence in Novogrod's Northern Dvina region. Wikipedia also tells me that the Novogrodians far outnumbered the Muscovites at the Battle of Shelo, but were disorganized, which allowed the Muscovites to win the battle and ultimately conquer the city. So perhaps a POD involving either Polish reinforcement, or better organized Novogrodians. I'm not sure how it'd work into Novogrodian unification of the Rus, but it at least maintains their independence and prevents the Muscovites from becoming the largest power in early Russia.
 
I think it's difficult simply because of the huge distances involved. A Republic of Novgorod ruling over the other Russian states is quite doable- but citizens of other Russian states participating in Novgordian politics probably is not. I'm basing this on the experience of Athens, Rome, and Venice, each of which strongly kept to its republican or democratic traditions at home, whilst squeezing its provinces dry and keeping them utterly downtrodden.

As for Russia saving the ERE, a motive is needed, beyond just saving their co-religionists. Perhaps if the major threat to the Empire comes from a power that also presents a clear danger to Russia too- some sort of Polish/Hungarian united Empire, perhaps? Turks probably won't cut it, because a power based in Anatolia and the Balkans doesn't really directly impact upon even southern Russia, let alone Novgorod.
 
Mm a very simple POD Otl the bishop of Novgorod was a supporter of the Muscovy faction. Grand Prince Dimity was the supporter of anti muscovite faction. At Shelon the loss was because the battle was initially against Pskov bur Muscov ambushed them. So the Bishop refused to commit his troops and Dimity dies. What you need is for the Bishop of Novgorod to die. Also at this point many Novrossyians Had given up fighting. What Dimity needs to do is blame the death of the bishop on Muscovy. This will rally Novgorod people who will want revenge. Next Dimity must form an alliance with Khan of Kazan. I believe if he approached the Khan and promised to offe tribute and become a vassal only if the khan declares war on Muscovy, the Khan of Tatars can be convinced. So when the Tatars invade Ivan intercepts. Them. In the ensuing battles have Ivan III die. However by his death the Tatars will be exausted in the war against Muscovy. Siezing that oppurtunity Novgorod invades Muscovy. Next have Polish Lithuania avert it's focus from the east somehow. Otherwise Polish Lithuanian forces will take Moscow. Hope my rough outline helped:)
 
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