June 1855. In August, the Russians again made an attack towards the base at Balaclava, which was defended by the French, newly arrived Sardinian and Ottoman troops. The resulting Battle of the Chernaya was a defeat for the Russians, who suffered heavy casualties. For months, each side had been building forward rifle pits and defensive positions, which resulted in many skirmishes. Artillery fire aimed to gain superiority over the enemy guns. The final assault was made on , when another French bombardment (the sixth) was followed by an assault by the French Army on and resulted in the French capture of the Malakoff fort. The Russians failed to retake it and their defences collapsed. Meanwhile, the British assaulted the Great Redan, a Russian defensive battlement just south of the city of Sevastopol, a position that had been attacked repeatedly for months. Whether the British captured the Redan remains in dispute: Russian historians recognise only the loss of the Malakhov Kurgan, a key point of defence, claiming that all other positions were retained. What is agreed is that the Russians abandoned the positions, blew up their powder magazines and retreated to the north. The city finally fell on 9 September 1855, after a 337-day-long siege. Both sides were now exhausted, and no further military operations were launched in Crimea before the onset of winter. The main objective of the siege was the destruction of the Russian fleet and docks and took place over the winter. On 28 February, multiple mines blew up the five docks, the canal, and three locks. Azov campaign In early 1855, the allied Anglo-French commanders decided to send an Anglo-French naval squadron into the Azov Sea to undermine Russian communications and supplies to besieged Sevastopol. On 12 May 1855, Anglo-French warships entered the Kerch Strait and destroyed the coast battery of the Kamishevaya Bay. Once through the Kerch Strait, British and French warships struck at every vestige of Russian power along the coast of the Sea of Azov. Except for Rostov and Azov, no town, depot, building or fortification was immune from attack, and Russian naval power ceased to exist almost overnight. This Allied campaign led to a significant reduction in supplies flowing to the besieged Russian troops at Sevastopol. On 21 May 1855, the gunboats and armed steamers attacked the seaport of Taganrog, the most important hub near Rostov on Don. The vast amounts of food,