The Crimean campaign opened in September 1854. In seven columns, 400 ships sailed from Varna, each steamer towing two sailing ships. Anchoring on 13 September in the bay of Eupatoria, the town surrendered, and 500 marines landed to occupy it. The town and the bay would provide a fallback position in case of disaster.

Allied forces reached Kalamita Bay on the western coast of the Crimea and started disembarking on 14 September. Prince Alexander Sergeyevich Menshikov, commander of Russian forces in the Crimea, was taken by surprise. He had not thought the allies would attack so close to the onset of winter, and had failed to mobilize sufficient troops to defend Crimea.

The British troops and cavalry took five days to disembark. Many of the men were sick with cholera and had to be carried off the boats. No facilities for moving equipment overland existed, so parties had to be sent out to steal carts and wagons from the local Tatar farms. The only food or water for the men was the three days' rations they had been given at Varna. No tents or kitbags were offloaded from the ships, so the soldiers spent their first nights without shelter, unprotected from the heavy rain or the blistering heat.

Despite the plans for a surprise attack on Sevastopol being undermined by the delays, six days later on 19 September, the army finally started to head south, with its fleets supporting them. The march involved crossing five rivers: the Bulganak, the Alma, Kacha, Belbek, and Chernaya. The next morning, the Allied army marched down the valley to engage the Russians, whose forces were on the other side of the river, on the Alma heights.