Olelkovych [Олелькович; Olel’kovyč] (Polish: Olelkowicz). A family of Orthodox appanage princes in the Lithuanian-Ruthenian state. They were descended from Volodymyr, the son of Grand Duke Algirdas of Lithuania (see Volodymyr, son of Algirdas). His son, Olelko Volodymyrovych, from whom the family name is derived, and grandson, Semen Olelkovych, were the last Ruthenian princes of Kyiv. Olelko's other son, Mykhailo Olelkovych, became the prince of Slutsk principality in Belarus and conspired to assassinate King Casimir IV Jagiellończyk. Mykhailo's son, Semen (d 14 November 1505), was an unsuccessful candidate for the Lithuanian throne after the death of Casimir IV in 1492. Semen's son, Yurii (b ca 1492, d 17 April 1542), was a member of the Council of Lords and supported Prince Kostiantyn Vasyl Ostrozky, who married his sister, Aleksandra, ca 1524. Yurii was close to King Sigismund II Augustus, married Princess Helena Radziwiłł in 1530, and owned enormous latifundia in Belarus, with over 40,000 peasants. Yurii's son, Yurii (b ca 1531, d 9 November 1578), was also a member of the Council of Lords and became a Polish senator in 1577. He transformed Slutsk into a center of Orthodox culture and was buried at the Kyivan Cave Monastery. His son, also Yurii (b 17 August 1559, d 6 May 1586), was also buried there. His orphaned daughter, Sofiia (b 1 May 1585, d 9 March 1612), married Prince Janusz Radziwiłł in 1600, after which Slutsk principality was ruled by the Radziwiłł family.
[This article originally appeared in the Encyclopedia of Ukraine, vol. 3 (1993).]