In 1806, the rebels twice dispatched the diplomat Petar Ičko to Constantinople to negotiate with the Porte. The two parties eventually reached an understanding, which came to be known as Ičko's Peace, in which the Ottomans agreed to grant the rebels extensive autonomy. Due to the Balkans' poor communications and transport infrastructure, it took several months for news of the Porte's offer to reach the rebels. In August 1806, the rebels defeated the Ottomans at the Battle of Mišar. Later that month, they scored another victory at the Battle of Deligrad. Smederevo was captured in November and made the capital of Karađorđe's revolutionary state. Belgrade, with the exception of its imposing fortress, fell in early December. The outbreak of the Russo-Ottoman War that month, compounded by Russia's avowal to provide extensive materiel and financial support to the rebels should they continue fighting, convinced Karađorđe not to accept anything short of complete independence. He promptly refused to accept the terms of the agreement negotiated by Ičko.