Less well-known is an opera by the Belarusian-Polish-Lithuanian composer Prince Antoni Radziwiłł (1775-1833) - the opera is sung in Belarusian and is available online (you are unlikely to find it commercially!). The duet for Faust and Gretchen is a particularly popular piece in the concert repertoire locally. Radziwiłł was a person of influence, being a Reichsfürst and Duke-Governor (Statthalter) in the Kingdom of Prussia (actually rather more complicated - see
http://en.wikipedia.org/wiki/Antoni_Radziwi%C5%82%C5%82 - and maybe it was because of this and his significant patronage of the arts that Goethe himself helped him in writing the opera. Interestingly his daughter nearly married Kaiser Wilhelm I.