Boris III (30.01.1894, Sofia - 28.08.1943, Sofia) - Tsar of Bulgaria in 1918-1943, from German Saxe-Coburg-Gotha dynasty. He was the eldest son of Tsar Ferdinand I (1861-1948), who abdicated in his benefit after the defeat of Bulgaria during the World War I.
Boris participated in the Balkan wars (1912-1913) and the World War I (1915-1918) as staff liaison officer (captain, major, lieutenant colonel) of the Bulgarian army. He graduated the Military Academy in 1915 and received the military rank Major-General in 1918.
Boris III sanctioned the coup d'etat on June 9, 1923 which removed the government of the Bulgarian Agrarian National Union led by Prime Minister Alexander Stamboliyski, who was against monarchy in Bulgaria. The political situation remained unstable, and Boris III fortunately escaped St. Nedelya Church assault even (terrorist attack carried on April 16, 1925 by Bulgarian communists and anarchists). After the coup on May 19, 1934 the new government repealed the Tarnovo Constitution, dissolved the National Assembly and prohibited political parties; de facto Boris III took all political power to his hands (however, parliamentary elections are held and there was a legal governmental opposition). Boris III married Italian princess Giovanna of Savoy in 1930, they had two children - Princess Marie Louise (born in 1933) and Prince Simeon (born in 1937).
After the beginning of World War II, Boris III directed Bulgaria towards neutrality. With the help of Germany and USSR, Bulgaria managed to return back Southern Dobrudja in 1940 which was taken by Romania in 1918. Nevertheless, Boris III declined Soviet offer to peace and friendship in 1940, and in January 1941 he agreed to join Tripartite (Berlin) Pact, which was signed by Bulgaria on March 1. In March-April 1941 German troops attacked Yugoslavia and Greece from the Bulgarian territory. As several territories (Morava Valley, Vardar Macedonia, Eastern Macedonia and Thrace) came after that under Bulgarian administration, Boris III received the title "Unitor" in Bulgaria. After the outbreak of the war with USSR in June 1941, albeit a German ally, Bulgaria continued to maintain diplomatic relations with USSR and did not send any troops to the Eastern Front (Boris III was a dedicated pacifist who took also into consideration strong pro-Russian spirits among Bulgarian population). But on December 13, 1941 Bulgaria declared war to UK and USA.
Tsar Boris III unexpectedly died on August 28, 1943 shortly after returning back to Sofia from a visit to Hitler (so there were assumptions that he was poisoned according to Hitler's order because of refusal to send Bulgarian jews to German concentration camps and to send Bulgarian soldiers against USSR; nevertheless, the official reason of his death was the heart attack). Boris III was succeeded by his infant son, Simeon II, and the Regency Council (included Prince Kyril, Prime Minister Bogdan Filov and Lt. General Nikola Mikhov) elected by the National Assembly was established that time.