On 15 February 1940, following the resignation of Georgi Kyoseivanov, Filov was appointed prime minister of the Kingdom of Bulgaria. Filov was an ally of Tsar Boris III of Bulgaria.
On February 15, 1940, following Georgi Kyoseivanov's step down as prime minister, Filov took office in Bulgaria. Filov was a confidant of Tsar Boris III of Bulgaria.