I randomly happened upon a article about Tver being, at one point, a rival to early Moscow for supremacy in Russia, and they mentioned that Tver used to be a land of bogs and just generally being a not so nice place and then that it was vying with Moscow for dominance in Russia. How did a town like that become so important?
The viceroy of the Horde had his residence in Tver. But in 1327 there was an uprising which resulted in the murder of the viceroy (at that time Shevkal) and which was suppressed with the aid of Muscowy. The bogged, cold, inhospitable towns on the North Eastern rim of what used to be Rus' have grown so insanely in wealth and prominence because here all the goods were loaded to follow the Volga river for the Tatar strongholds of Sarai, Kazan and Astrakhan. Since then these northern swamp towns came to be known as "the Golden Ring".