The Svyatogor was a large experimental Russian aircraft, constructed by Vasily Slesarev in 1916. The aircraft was named after the mythological hero Svyatogor. The Slesarev Svyatogor never flew (thanks Kim!)

As suitable engines were hard to come by, Slesarev tried to mount some  2 x 300hp Mercedes engines that had been taken from a downed Zeppelin driving pusher propellers by shafts and gears. He contacted the French when this did not work out, and received some 220hp Renault engines.

These arrived in January 1916. Despite being without money, the construction of the revised design continued. The project stalled, however, with the transmission problems and the death of Slesarev in 1921. 

https://en.wikipedia.org/wiki/Slesarev_Svyatogor

https://www.vintag.es/2016/09/the-slesarev-svyatogor-see-pictures-of.html

http://flyingmachines.ru/Site2/Crafts/Craft28198.htm

https://www.romanovempire.org/media/syatogor-heavy-bomber-wheels-incident-1916-3d1d68