#Onthisday in history 18th June 860 A.D. The siege of Constantinople took place, this was a vital military expedition of the Rus’ Khaganate which was recorded in the byzantine and western European sources. Upon the reason as to why the construction of the fortress built of Sarkel by the Byzantine Empire, was to stop the Russian trade along the Don river in favour of the Khazars.
Byzantine sources have suggested that the Rus caught Constantinople unprepared, because the Byzantine Empire was pre-occupied with the on-going wars of the Byzantine-Arabs, and that they would not be able to cope with the Rus threat. The Rus retreated and withdrew which was seen as victorious and a cause for debate.