The Crimean War formally commenced with the declaration of war by the Ottoman Empire against the Russian Empire, driven by a series of provocations and territorial disputes. The roots of the conflict lay in the declining power of the Ottoman Empire and the ambitions of Russia to expand its influence, particularly in the Balkans and the Black Sea. The tensions escalated when Russia occupied the Principalities of Moldavia and Wallachia, territories nominally under Ottoman control. In response, the Ottomans sought to fortify their standing by rallying support from Great Britain and France, fearing a greater Russian expansion would endanger their sovereignty.

The war would evolve into a broader European conflict, with Britain and France joining the Ottomans against Russia. This marked the first modern conflict that utilized extensive journalism and new technologies, such as the telegraph, making the war highly publicized. Major battles, including those at Balaclava and Inkerman, showcased the tactical complexities and challenges of warfare during this era. The Siege of Sevastopol became one of the most significant military engagements, emphasizing the costly nature of the conflict for all involved.

With a culmination of military and diplomatic engagements, the Crimean War concluded in 1856 with the Treaty of Paris, altering the balance of power in Europe. This conflict was pivotal for military innovations and revealed the fragility of empires in the face of nationalist movements and modern warfare. The resulting shifts would influence geopolitical relations for decades to come, foreshadowing alliances and rivalries leading into the 20th century.