The port of Balaclava was crucial in maintaining the supply lines for the Allied siege of Sevastapol. The Russian attack on it on 25th October 1854 therefore posed a major threat to the survival of the Allied cause. The battle took place in four stages, first of which was the successful Russian attack on the redoubts of Balaclava. This was followed by the action of "the thin red line" in which an assortment of about 700 British troops, some invalids, were abandoned by their Turkish allies and forced to successfully resist the attack of four squadrons of Russian cavalry. The subsequent charge of the Heavy Brigade which neutralised the threat to nearby Kadikoi was followed by the most famous part of the battle: the charge of the Light Brigade. Immortalised by Tennyson's poem, this action was not so much glorious as a major example of military ineptitude. Divisions at the top of the British command structure, and confusion in the transmission of orders prompted Lord Cardigan and the men of the Light Brigade to attack the Don Battery which was protected by infantry and more artillery on its flanks. John Sweetman looks at these events and analyses their collective significance in the outcome of the Battle of Balaclava.