European balance of power in the context of "Great Powers"

The Crimean War was fought between the Russian Empire and an alliance of the Ottoman Empire, the Second French Empire, the United Kingdom of Great Britain and Ireland, and the Kingdom of Sardinia-Piedmont from October 1853 to February 1856. Geopolitical causes of the war included the "Eastern question" (the decline of the Ottoman Empire), expansion of Imperial Russia in the preceding Russo-Turkish wars, and the British and French preference to preserve the Ottoman Empire to maintain the balance of power in the Concert of Europe.

The war's proximate cause was a dispute between France and Russia over the rights of Catholic and Orthodox minorities in Palestine. After the Sublime Porte refused Tsar Nicholas I's demand that the Empire's Orthodox subjects be placed under his protection, Russian troops occupied the Danubian Principalities in July 1853. The Ottomans declared war on Russia in October. Fearing the growth of Russian influence and compelled by public outrage over the annihilation of the Ottoman squadron at Sinop, Britain and France joined the war on the Ottoman side in March 1854. The Russian advance was halted at Silistria in June.

At the Congress of Berlin (13 June – 13 July 1878), the major European powers revised the territorial and political terms imposed by the Russian Empire on the Ottoman Empire by the Treaty of San Stefano (March 1878), which had ended the Russo-Turkish War of 1877–1878. The Congress was the result of escalating tensions; particularly British opposition to Russian hegemony over the Ottoman Empire in the Balkans, through the creation of a Russian-aligned 'Greater Bulgaria'. To secure the European balance of power in favour of its splendid isolation achieved after the Crimean War, Britain stationed the Mediterranean Fleet near Constantinople to enforce British demands. To avoid war, Otto von Bismarck, Chancellor of the newly formed German Empire, was asked to mediate a solution that would restore the Ottoman Empire's position as a counterbalance to Russian influence in the Mediterranean and the Balkans, in line with the principles of the 1856 Treaty of Paris.

Attended by delegates from Europe's then six great powers: Russia, Great Britain, France, Austria-Hungary, Italy, and Germany; the Ottomans as well as representatives of four Balkan states (Greece, Serbia, Romania and Montenegro), the Congress culminated in the Treaty of Berlin (13 July 1878). This agreement essentially dismantled the autonomous Greater Bulgarian State envisaged at San Stefano, and reorganised the borders of south-eastern Europe. The main results were the Austro-Hungarian forcible occupation of Bosnia and Herzegovina, the British de facto annexation of Cyprus under false pretenses, and the formal recognition of the self-declared independence of Romania, Serbia and Montenegro; allies of Russia in the previous war. While the settlement averted war, it exacerbated nationalist grievances in the Balkans and deepened the rivalry between Britain and Russia (The Great Game), contributing to long-term regional instability that foreshadowed the Balkan Wars and World War I.

The Treaty of Berlin (formally the Treaty between Austria-Hungary, France, Germany, Great Britain and Ireland, Italy, Russia, and the Ottoman Empire for the Settlement of Affairs in the East) was signed on 13 July 1878. In the aftermath of the Russian victory against the Ottoman Empire in the Russo-Turkish War of 1877–1878, the major powers restructured the map of the Balkan region. They reversed some of the extreme gains claimed by Russia in the preliminary Treaty of San Stefano, but the Ottomans lost their major holdings in Europe. It was one of three major peace agreements in the period after the 1815 Congress of Vienna. It was the final act of the Congress of Berlin (13 June – 13 July 1878) and included the United Kingdom, Austria-Hungary, France, Germany, Italy, Russia and the Ottoman Empire. Chancellor of Germany Otto von Bismarck was the chairman and dominant personality.

The most important task of the Congress was to decide the fate of Bulgaria, but Bulgaria itself was excluded from participation in the talks, at Russian insistence. At the time, as it was not a sovereign state, Bulgaria was not a subject of international law, and the same went for the Bulgarians themselves. The exclusion was already an established fact in the great powers' Constantinople Conference, which had been held one year before without any Bulgarian participation.

The War of the Spanish Succession was a European great power conflict, fought between 1701 and 1714. The death of Charles II of Spain in November 1700 without children resulted in a succession struggle between rival claimants. In his will, Charles named his heir as Philip of Anjou, who was backed by his grandfather Louis XIV. His opponent, Archduke Charles of Austria, was supported by the Grand Alliance. Significant related conflicts include the Great Northern War (1700–1721) and Queen Anne's War (1702–1713).

Although no longer the predominant power in Europe, the Spanish Empire remained a vast global power, including the Spanish Netherlands, large parts of Italy, the Americas and the Spanish East Indies. Its union with either France or Austria threatened the European balance of power, and the proclamation of Philip as king of Spain on 16 November 1700 led to war. Although by 1709 the Grand Alliance had forced France onto the defensive, Philip had confirmed his position in Spain, the ostensible cause of the war.

Catherine II (born Princess Sophia Augusta Frederica, Russian: Екатерина Алексеевна Романова; 2 May 1729 – 17 November [O.S. 6 November] 1796), commonly known as Catherine the Great, was the reigning Empress of Russia from 1762 to 1796. She came to power after a coup d'etat against her husband, Peter III. Her long reign helped Russia thrive under a golden age under the Enlightenment. This renaissance led to the founding of many new cities, universities, and theatres, along with large-scale immigration from the rest of Europe and the recognition of Russia as one of the great powers of Europe.

After overthrowing and possibly assassinating her husband and her subsequent rule of the Russian Empire, Catherine often relied on noble favourites such as Count Grigory Orlov and Grigory Potemkin. Assisted by highly successful generals such as Alexander Suvorov and Pyotr Rumyantsev and admirals such as Samuel Greig and Fyodor Ushakov, she governed at a time when the Russian Empire was expanding rapidly by conquest and diplomacy. In the west, she installed her former lover to the throne of Poland, which was eventually partitioned. In the south, the Crimean Khanate was annexed following victories over the Bar Confederation and the Ottoman Empire in the Russo-Turkish War. With the support of Great Britain, Russia colonised the territories of New Russia along the coasts of the Black and Azov Seas. In the east, Russians became the first Europeans to colonise Alaska, establishing Russian America.

The Congress of Vienna of 1814–1815 was a series of international diplomatic meetings to discuss and agree upon a possible new layout of the European political and constitutional order after the downfall of the French Emperor Napoleon Bonaparte. Participants were representatives of all European powers (other than the Ottoman Empire) and other stakeholders. The Congress was chaired by Austrian statesman Klemens von Metternich, and was held in Vienna from September 1814 to June 1815.

The objective of the Congress was to provide a long-term peace plan for Europe by settling critical issues arising from the French Revolutionary Wars and the Napoleonic Wars through negotiation. The goal was not simply to restore old boundaries, but to resize the main powers so they could balance each other and remain at peace, being at the same time shepherds for the smaller powers. More generally, conservative leaders like Metternich also sought to restrain or eliminate republican, liberal, and revolutionary movements which, from their point of view, had upended the constitutional order of the European ancien régime.

In diplomatic history, the Eastern question was the issue of the political and economic instability in the Ottoman Empire from the late 18th to early 20th centuries and the subsequent strategic competition and political considerations of the European great powers in light of this. Characterized as the "sick man of Europe", the relative weakening of the empire's military strength in the second half of the nineteenth century threatened to undermine the fragile balance of power system largely shaped by the Concert of Europe. The Eastern question encompassed myriad interrelated elements: Ottoman military defeats, Ottoman institutional insolvency, the ongoing Ottoman political and economic modernization programme, the rise of ethno-religious nationalism in its provinces, and Great Power rivalries. In an attempt to triangulate between these various concerns, the historian Leslie Rogne Schumacher has proposed the following definition of the Eastern Question:

The period in which the Eastern Question was internationally prominent is also open to interpretation. While there is no specific date on which the Eastern question began, the Russo-Turkish War of 1828–1829 brought the issue to the attention of the European powers, Russia and Britain in particular. As the dissolution of the Ottoman Empire was believed to be imminent, the European powers engaged in a power struggle to safeguard their military, strategic and commercial interests in the Ottoman domains. Imperial Russia stood to benefit from the decline of the Ottoman Empire; on the other hand, Austria-Hungary and United Kingdom deemed the preservation of the Empire to be in their best interests. The Eastern question was put to rest after the First World War, one of the outcomes of which was the collapse and division of the Ottoman holdings.