Crimean War - Wikipedia

On September 20, 1854, at the Battle of the Alma, the first major battle of Crimean War, the British and French alliance defeated the Russians. From the article:

"While the churches worked out their differences and came to an agreement, Nicholas I of Russia and the French Emperor Napoleon III refused to back down. Nicholas issued an ultimatum that the Orthodox subjects of the Empire be placed under his protection. Britain attempted to mediate and arranged a compromise that Nicholas agreed to. When the Ottomans demanded changes, Nicholas refused and prepared for war. Having obtained promises of support from France and Britain, the Ottomans declared war on Russia in October 1853.

The war started in the Balkans in July 1853, when Russian troops occupied the Danubian Principalities[6] (part of modern Romania), which were under Ottoman suzerainty, then began to cross the Danube. Led by Omar Pasha, the Ottomans fought a strong defensive campaign and stopped the advance at Silistra. A separate action on the fort town of Kars in eastern Anatolia led to a siege, and a Turkish attempt to reinforce the garrison was destroyed by a Russian fleet at Sinop. Fearing an Ottoman collapse, France and Britain rushed forces to Gallipoli. They then moved north to Varna in June 1854, arriving just in time for the Russians to abandon Silistra. Aside from a minor skirmish at Köstence (today Constanța), there was little for the allies to do. Karl Marx quipped, "there they are, the French doing nothing and the British helping them as fast as possible".[8]

Frustrated by the wasted effort, and with demands for action from their citizens, the allied force decided to attack Russia's main naval base in the Black Sea at Sevastopol on the Crimean peninsula. After extended preparations, the forces landed on the peninsula in September 1854 and marched their way to a point south of Sevastopol after the successful Battle of the Alma. The Russians counterattacked on 25 October in what became the Battle of Balaclava and were repulsed, but at the cost of seriously depleting the British Army forces. A second counterattack, at Inkerman, ended in stalemate. The front settled into a siege and led to brutal conditions for troops on both sides. Smaller actions were carried out in the Baltic, the Caucasus, the White Sea and in the North Pacific.

Sevastopol fell after eleven months, and neutral countries began to join the Allied cause. Isolated and facing a bleak prospect of invasion from the west if the war continued, Russia sued for peace in March 1856. This was welcomed by France and Britain, as their subjects were beginning to turn against their governments as the war dragged on. The war was ended by the Treaty of Paris, signed on 30 March 1856. Russia was forbidden from hosting warships in the Black Sea. The Ottoman vassal states of Wallachia and Moldavia became largely independent. Christians there were granted a degree of official equality, and the Orthodox Church regained control of the Christian churches in dispute.[9]:415

The Crimean War was one of the first conflicts to use modern technologies such as explosive naval shells, railways and telegraphs.[10](Preface) The war was one of the first to be documented extensively in written reports and photographs. As the legend of the "Charge of the Light Brigade" demonstrates, the war quickly became an iconic symbol of logistical, medical and tactical failures and mismanagement. The reaction in the UK was a demand for professionalisation, most famously achieved by Florence Nightingale, who gained worldwide attention for pioneering modern nursing while treating the wounded."