What is the context?

Circassian migration to the Ottoman Empire in the 19th Century

Following the conquest of the north Caucasus, the Russian Empire implemented a policy of evicting the surviving Circassians from their ancestral territories. The Russian General, Yevdokimov, was given the task of driving the remaining Circassian inhabitants out of their mountain strongholds to face exile or become Christians and join the armies of the Tsar or settle around the Kuban where the Cossacks were now in control. This policy was enforced by mobile units of Russian infantry and Cossack cavalry.  

 

During May 1864 many Circassians gathered from all corners of the country to make a last stand in the valley of the Aibgo in the heart of the mountains. For four days (7-11 May 1864) Russian forces were repulsed with great losses. Heavy artillery was then brought up and strafed the valley. There were no survivors. The Russian capture of this little valley was the last act of the Russo-Circassian war.

S.D. Shenfield, The Circassians: A forgotten genocide? in (eds) M. Levene and P. Roberts, The Massacre in History, New York 2006