Prince Kyril of Bulgaria, Prince of Preslav (Kyril Heinrich Franz Ludwig Anton Karl Philipp) (17 November 1895 in Sofia – 1 February 1945 in Sofia) was the second son of Ferdinand I of Bulgaria and his first wife Marie Louise of Bourbon-Parma. He was a younger brother of Boris III of Bulgaria and a prince regent of the Kingdom of Bulgaria from 1943 to 1944.

He was born on 17 November 1895 in Sofia as the second son of Ferdinand I of Bulgaria and his first wife Marie Louise of Bourbon-Parma.

In September 1936 Prince Kyril accompanied King Edward VIII on a whistle-stop tour of Iceland. Present at the death of his brother, Tsar Boris, on 28 August 1943, Prince Kyril was appointed head of a regency council by the Bulgarian parliament, to act as Head of State until the late Tsar's son, Simeon II of Bulgaria, became 18.

Prince Kyril, with the widowed Tsaritsa, Giovanna of Savoy, daughter of the Italian king, led the state funeral for his brother Tsar Boris III on 5 September 1943 at the Alexander Nevsky Cathedral, Sofia, thereafter proceeding across the city to the main railway station where the funeral train waited to take the body to the 12th century Rila Monastery in the mountains. Thereafter the three consecutive governments made efforts to extricate themselves from Bulgaria's agreements with Germany, notably that which permitted their use of the railway to Greece and the German troops stationed along it for protection. A Bulgarian delegation travelled to Cairo in an attempt to negotiate with the United States and Great Britain but failed, the latter refusing to meet them without the participation of the Soviet Union.

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