Jasko of Teczyn, Castellan of Krakow

 In the book Jasko of Teczyn is a Catellan of Krakow.

Jan (or Jasko) of Teczyn, (born between 1408–1410, died on July 6, 1470) - the castellan of Kraków in the years 1459–1470, the voivode of Kraków in the years 1438–1459, the voivode of Sandomierz in the years 1437–1438, the castellan of Wojnica in the years 1435–1437, guardian of the Kraków land in the years 1434–1436, the starost of Lublin in the years 1434–1438, the castellan of Biecz in the years 1433–1435.

For a quarter of a century, he was the most powerful magnate in Poland. It seems that the book's character is based on Jan, but the story itself takes place around 1410.

Rus'

More precisely - Kievan Rus'

Kievan Rus' was a loose federation in Eastern Europe and Northern Europe from the late 9th to the mid-13th century. Encompassing a variety of peoples, including East Slavic, Norse, Baltic, and Finnic. It was ruled by the Rurik dynasty. The modern nations of Belarus, Russia, and Ukraine all claim Kievan Rus' as their cultural ancestors, with Belarus and Russia deriving their names from it. At its greatest extent in the mid-11th century, Kievan Rus' stretched from the White Sea in the north to the Black Sea in the south and from the headwaters of the Vistula in the west to the Taman Peninsula in the east, uniting many East Slavic tribes.

Duchess Alexandra

Alexandra of Lithuania, Duchess consort of Masovia

Alexandra was the youngest daughter of Algirdas, Grand Duke of Lithuania, and his second wife, Uliana of Tver. Though Alexandra's exact date of birth is not known, it is thought that she was born in the late 1360s or early 1370s. In 1387, she married Siemowit IV, Duke of Masovia, and bore him thirteen children.