Boris III (Bulgarian: Борѝс III; Boris Treti; 30 January [O.S. 18 January] 1894 – 28 August 1943) was the Tsar of the Kingdom of Bulgaria from 1918 until his death in 1943.
The eldest son of Ferdinand I, Boris assumed the throne upon the abdication of his father in the wake of Bulgaria's defeat in World War I. Under the 1919 Treaty of Neuilly, Bulgaria was forced to cede various territories, pay crippling war reparations, and greatly reduce the size of its military. That same year, Aleksandar Stamboliyski of the Bulgarian Agrarian National Union became prime minister. After Stamboliyski was overthrown in a coup in 1923, Boris recognized the new government of Aleksandar Tsankov, who harshly suppressed the Bulgarian Communist Party and led the nation through a brief border war with Greece. Tsankov was removed from power in 1926, and a series of prime ministers followed until 1934, when the corporatist Zveno (Bulgarian: Звено) movement staged a coup and outlawed all political parties. Boris opposed the Zveno government and overthrew them in 1935, eventually installing Georgi Kyoseivanov as prime minister. For the remainder of his reign, Boris would rule as a de facto absolute monarch, with his prime ministers largely submitting to his will.
