The Prince of Novgorod, Peter the Great, did claim to be Roman Emperor for a while when he built the abortive Greco-Roman-styled city "St. Petersburg" on the Black Sea. However, that obviously didn't pan out.
If you go to Petersborg today you can still see most of the intact “Russian Old Town.” Of course, it’s dwarfed in size by the “Swedish New Town” on the other side of the river.