Initially, Emperor Alexander I was reluctant to concentrate large forces against the Ottoman Empire while his relations with Napoleonic France were still uncertain and the main part of his army was occupied fighting against Napoleon in Prussia. A massive Ottoman offensive aimed at Russian-occupied Bucharest, the Wallachian capital, was promptly checked at Obilesti by as few as 4,500 soldiers commanded by Mikhail Miloradovich (June 2, 1807). In Armenia, the 7,000-strong contingent of Count Gudovich destroyed the Turkish force of 20,000 at Arpachai (June 18). In the meantime, the Russian Imperial Navy under Dmitry Senyavin blockaded the Dardanelles and defeated the Ottoman fleet in the Battle of the Dardanelles, after which Selim III was deposed. The Ottoman fleet was destroyed the following month in the Battle of Athos, thus establishing Russian supremacy on sea.