Charles XIII of Sweden vs Ferdinand I of Bulgaria

Charles XIII, as regent and later king, oversaw the conclusion of the Finnish War against Russia. The Treaty of Fredrikshamn ceded Finland to Russia, ending centuries of Swedish rule over the region.

Charles XIII was crowned King of Sweden after the deposition of Gustav IV Adolf. His coronation followed the adoption of the 1809 constitution, which established a balance of power between the king and the Riksdag.

Charles XIII, having no legitimate heirs, adopted the French Marshal Jean-Baptiste Bernadotte as his successor. Bernadotte became Crown Prince Charles John and effectively ruled Sweden, founding the Bernadotte dynasty.

Charles XIII, under the influence of Crown Prince Charles John, accepted the Treaty of Kiel and the Convention of Moss, which forced Norway into a personal union with Sweden. Charles XIII became King of Norway as Charles II.

Charles XIII died in Stockholm at age 69. His death ended the Holstein-Gottorp dynasty's rule in Sweden, as he was succeeded by his adopted son, Charles XIV John (Bernadotte).

Ferdinand I proclaimed Bulgaria's full independence from the Ottoman Empire, declaring himself Tsar. This ended Ottoman suzerainty and established Bulgaria as a sovereign kingdom.

Ferdinand I led Bulgaria into the First Balkan War against the Ottoman Empire. Bulgaria achieved major victories, capturing Adrianople and much of Thrace, significantly expanding its territory.

Ferdinand I ordered an attack on former allies Serbia and Greece, triggering the Second Balkan War. Bulgaria was defeated by a coalition including Romania and the Ottoman Empire, losing most of its gains.

After Bulgaria's defeat in World War I, Ferdinand I abdicated in favor of his son Boris III. He went into exile, ending his reign amid national crisis and territorial losses.