On 2 July, Diebitsch launched the Trans-Balkan offensive, the first in Russian history since the 10th-century campaigns of Svyatoslav I. The contingent of 35,000 Russians moved across the mountains, circumventing the besieged Shumla on their way to Constantinople. The Russians captured Burgas ten days later, and the Turkish reinforcement was routed near Sliven on 31 July. By 22 August, the Russians had taken Adrianople, reportedly causing the Muslim population in the city to leave. The Ottoman palace in Adrianople, "Saray-i Djedid-i Amare", was heavily damaged by Russian troops.