and compelled the khan to establish his headquarters in the Crimea. Religion and death According to modern historians, "For Gediminas and Algirdas, retention of paganism provided a useful diplomatic tool and weapon ... that allowed them to use promises of conversion as a means of preserving their power and independence". Hermann von Wartberge and Jan Długosz described Algirdas as a pagan until his death in 1377. Contemporary Byzantine accounts support the Western sources; Patriarch Neilos described Algirdas as "fire-worshipping prince" and another patriarch, Philotheos, excommunicated all Ruthenian noblemen who helped the "impious" Algirdas. His pagan beliefs were also mentioned in 14th-century Byzantine historian Nicephorus Gregoras' accounts. After his death, Algirdas was burned on a ceremonial pyre with 18 horses and many of his possessions in a forest near Maišiagala, probably in the Kukaveitis forest shrine located at . His alleged burial site has undergone archaeological research since 2009. Algirdas' descendants include the Trubetzkoy, Czartoryski and Sanguszko families. Although Algirdas was said to have ordered the death of Anthony, John, and Eustathius of Vilnius, who were later glorified as martyrs of the Russian Orthodox Church, the 16th-century Bychowiec Chronicle and 17th-century Hustynska Chronicle maintain that he converted to Orthodox Christianity some time before his marriage to Maria of Vitebsk in 1318. Several Orthodox churches were built in Vilnius during his reign, but later assertions about his baptism are uncorroborated by contemporary sources. Despite contemporary accounts and modern studies, however, some Russian historians (such as Batiushikov) claim that Algirdas was an Orthodox ruler. The Kiev Monastery of the Caves' commemorative book, underwritten by Algirdas' descendants, recorded his baptismal name as Demetrius during the 1460s. Following Wojciech Wijuk Kojałowicz and Macarius I, Volodymyr Antonovych writes that Algirdas took monastic vows several days before his death and was interred at the Cathedral of the Theotokos in Vilnius under the monastic name Alexius. Issue With Maria of Vitebsk: Andrei of Polotsk (1325 – 12 August 1399), Duke of Polock (1342–1387), Pskov (1342–1348) Demetrius I Starszy (1327 – 12 August 1399 in the Battle of the Vorskla River), Duke of Bryansk (1356–1379 and 1388–1399) Constantine (died before 30 October 1390), Prince of Czartorysk. According to J. Tęgowski, he may be son of Koriat. Vladimir Olgerdovich (died after October 1398), Prince of Kiev (1362–1394), Kopyl, Sluck. Ancestor of Olelkovich and Belsky families. Fiodor (Theodore; died in 1399), Prince of Rylsk (1370–1399), Ratnie (1387–1394), Bryansk (1393) Fiedora, wife