But within two years the Turks drove him back across the Dnieper .
On September 19 , 1676 , Doroshenko surrendered to Samylovych , who declared himself hetman of a united Ukraine .
Within two years the Turks drove Doroshenko back across the Dnieper .
On September 19 , 1676 , Doroshenko surrendered to Samylovych , who declared himself hetman of a united Ukraine .