Was browsing and found this today. Seller had it listed as an unknown European medal or token. Lots of pics, and helpfully, he included measurements... (!) I was the only bidder, and won it for my only bid.
Russia - 1810 - Alexander I. Silver Medal commemmorating the 100th Anniversary of the Annexation of Riga by Peter the Great in 1710. Dated July 4, 1810.


Reference: Diakov 336.1 (R2)
AR, (.868 fine?) 54mm, 62.5g (ASW 1.747 ozt?) Plain edge.
Heavy original toning.
Obverse: Laureate busts of Peter I (left) and Alexander I (right). The Latin inscription reads ILLI APERIEBANTUR URBUS PORTAE TIBI PATENT CIVIUM CORDA. Centered beneath the two busts above the exergue, in Cyrillic script, the name of the engraver, Carl de Leberecht, as C. LEBERECHT F.
Obverse Exergue: EX VOTO PUBL. SAECULARI PRIMO SUBJECTIONIS D. 4. IUL. 1810.
Reverse: The Imperial Russian Eagle, a cornucopia within its grasp, flies over a city view of Riga and its harbor. The Latin inscription reads PAX ET SALUS. Centered above the exergue, the city seal of Riga.
Reverse Exergue: C. LEBERECHT F. in Cyrillic script.
One of the original presentation medals is held by the Pushkin Museum in Moscow. The ANS also has an example in its collection.
An example sold at auction for £240 in January 2006 in Salisbury; another brought €500 in a Künker auction in July of 2014. A Russian auction house listed one for $3000 bid with a $3500 estimate (!!) in December 2007, it did not sell, not surprisingly; another in October 2008 for 65000-75000 rubles ($2500-$3000 at the time), also a no-sale.
Apparently the Russians seem to think this is worth a lot more than the rest of the world. Probably quite a bit more than Latvians do...
Just a little fun
ebay find & history lesson. Enjoy.