Greetings all,

Today we reflect on the Russian siege of Constantinople which began on July 18th in 860 AD: , a fleet of about 200 Rus vessels sailed into the Bosporus and began pillaging suburbs outside of Constantinople: 

https://en.wikipedia.org/wiki/Siege_of_Constantinople_(860)

This was in response to the construction of a Byzantine fort called the Sarkel which had been constructed on the river Don and restricted Russian trade on the river:

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

A fleet of about 200 Rus vessels sailed up the Bosporus and began pillaging the suburbs outside of Constantinople. The attack took the Byzantines by surprise as Emperor Michael III (and the Byzantine navy) were away from the city. What forces might have been available were fighting the Arabs at that time. The invasion continued until August 4 - when the raiders seem to have simply left after being unable to take the city itself. 

-Marcus Cassius Julianus