Yaroslav of Tver

Yaroslav III Yaroslavich (Russian: Ярослав Ярославич; 1230 – 9 September 1271) was the first Prince of Tver from 1247, and Grand Prince of Vladimir from 1263 until his death in 1271. All the later princes of Tver descended from him.

Yaroslav and his son Mikhail presided over Tver's transformation into one of the greatest centres of power in medieval Russia which would compete with Moscow.

Source: Wikipedia — https://en.wikipedia.org/wiki/Yaroslav_of_Tver