the rebel force. This Battle of Agra cleared all organised rebel forces from the area between Delhi and Cawnpore, although guerrilla bands remained. Shortly afterwards, Greathed received reinforcements from Delhi, and was superseded in command by Major General James Hope Grant. Grant reached Cawnpore late in October, where he received orders from the new commander-in-chief in India, Sir Colin Campbell, to proceed to the Alambagh, and transport the sick and wounded to Cawnpore. He was also strictly enjoined not to commit himself to any relief of Lucknow until Campbell himself arrived. Campbell was 64 years old when he left England in July 1857 to assume command of the Bengal Army. By mid-August, he was in Calcutta preparing his departure upcountry. It was late October before all preparations were completed. Fighting his way up the Grand Trunk Road, Campbell arrived in Cawnpore on 3 November. The rebels held effective control of large parts of the countryside. Campbell considered, but rejected, securing the countryside before launching his relief of Lucknow. The massacre of British women and children following the capitulation of Cawnpore was still in recent memory. In British eyes, Lucknow had become a symbol of their resolve. Accordingly, Campbell left 1,100 troops in Cawnpore for its defence, leading 600 cavalry, 3,500 infantry and 42 guns to the Alambagh, in what Samuel Smiles described as an example of the "women and children first" protocol being applied. British warships were dispatched from Hong Kong to Calcutta. The marines and sailors of the Shannon, Pearl and Sanspareil formed a Naval Brigade with the ships' guns (8-inch guns and 24-pounder howitzers) and fought their way from Calcutta until they met up with Campbell's force. The strength of the rebels investing Lucknow has been widely estimated from 30,000 to 60,000. They were amply equipped, the sepoy regiments among them were well trained, and they had improved their defences in response to Havelock's and Outram's first relief of the Residency. The Charbagh Bridge used by Havelock and Outram just north of the Alambagh had been fortified. The Charbagh Canal from the Dilkusha Bridge to the Charbagh Bridge was dammed and flooded to prevent troops or heavy guns fording it. Cannon emplaced in entrenchments north of the Gumti River not only daily bombarded the besieged Residency but also enfiladed the only viable relief path. However, the lack of a unified command structure among the sepoys diminished the value