Count Kyrylo Grygorovych Rozumovsky (Ukrainian: Кирило Григорович Розумовський, Russian: Кирилл Григорьевич Разумовский) (March 18, 1728 – January 1, 1803) was a Ukrainian Registered Cossack from the Kozelets regiment in north-eastern Ukraine, who served as the last Hetman of Left- (from 1750) and Right-Bank (from 1754) Ukraine until 1764; Rozumovsky was subsequently elected Hetman of the sovereign Zaporozhian Host in 1759, a position that he managed to nominally preserve until 1769, even though he had lost all power to exercise this office and abdicated in November 1764.
Kyrulo Rozum was appointed President of the Russian Academy of Sciences when he just turned 18 years old due to the influence of his brother, Oleksiy Grygorovych Rozumovsky, the morganatic husband of Empress Elisabeth.
In 1750, he was elected and subsequently appointed Hetman of the Ukrainian Cossacks, a title he held until Catherine II of Russia forced him to abdicate in 1764. During his reign, Baturyn was re-established as capital of the Hetmanate and Rozumovsky had opulent baroque palaces erected both in Baturyn as well as in Hlukhiv by the imperial architect Andrey Kvasov and Charles Cameron. He also planned to open a Ukrainian university in Baturyn.
In July 1762, Rozumovsky supported the coup d'état Catherine the Great staged against her husband, the legitimate ruler of the Russian Empire, Czar Peter III. Shortly thereafter, in May 1763, Kyrulo Rozumovsky, backed by the Heneralna Starshyna of the Hetmanate, declared the Ukrainian state's sovereignty and the heredity of the title in primogeniture for his descendants in the male line. Into the phase of the ensuing power struggle between the Hetman and the Czarina, fell the failed attempt to free the deposed Czar Ivan VI in Schluesselburg by one of Rozumovsky's followers, a young cossack noble by the name of Myrovych. However, Rozumovsky's active support or even tacit approval was never proven. In November 1764, the Hetman eventually gave in to the military threat exerted by the Empress and abdicated. From 1765 to 1766, he traveled extensively to Western Europe, yet always accompanied by a Russian "honour guard", which was a privilege associated with the rank of Field-Marshal, conveniently accorded to him by Catherine II. Effectively, Rozumovsky was banned from traveling to his Ukrainian homeland until the last bastion of the Hetmanate, the Zaporozhian Host, had been vanquished by Grigori Potemkin in 1776. Kyrulo Rozumovsky died in January 1803 in Baturyn, where he was interred according to his wishes without any pomp, in stark contrast to his rather flamboyant lifestyle.
Kyrulo had five sons, of whom Count Oleksiy Kyrulovych (1748-1822) was the Minister of Education in 1810-16, and Prince Andriy Rozumovsky (1752-1836) was the Russian plenipotentiary ambassador in Vienna in the years of the Congress 1814-1815. However, Andriy has become better known for his role as patron of Ludwig van Beethoven who dedicated three String Quartets, Op.59 1, 2 and 3, as well as the 5th and 6th Symphonies to him. Any living descendants in the male line of Kyrulo Rozumovsky arise from the progeniture of his fourth son Gregor Rozumovsky (1759-1837), who had to emigrate to Western Europe due to his critique of czarist totalitarian rule and acquired relative fame as natural scientist and member of a number of distinguished scientific societies in Austria, Germany and Switzerland.