CATHEDRAL OF THE ASSUMPTION — Uspenksy Sobor. Also known as the Cathedral of the Dormition. Commemorates the dormition (aka falling asleep, aka death of the Mother of God and her being taken to heaven). Located in the modern-day Moscow Kremlin, the original limestone structure was begun in 1326 and consecrated in 1327. The building presently on the site dates to the sixteenth century.

CHELUBEY — Called Chelubey by Russian chroniclers and Temir-Murza by his own countrymen, Chelubey was the champion for the Tatar side at the battle of Kulikovo. He was defeated by Aleksandr Peresvet.

CHERNOMOR — An old wizard and sea-king in Russian folklore whose name literally derives from “Black Sea.” With his thirty-three sons he would come out of the sea to guard the island of the swan-maiden in the fairy tale of Tsar Saltan.

CHYERTI (SINGULAR: CHYERT) — Devils. In this case a collective noun meaning the various spirits of Russian folklore. Another, and possibly better, term is nyechistiye sili, literally “unclean forces,” but that is an unwieldy mouthful for Anglophone readers.

DAN — Tribute; in this case, the tribute owed by the conquered Rus’ to their Mongol overlords.

DED GRIB — Grandfather Mushroom. There is no historical source for this one; he was inspired by and is a shout-out to a character in the old Soviet children’s movie Morozko.

DMITRII DONSKOI — Called Dmitrii Ivanovich in The Winternight Trilogy, he earned the moniker “of the Don” following his victory at the Battle of Kulikovo.

DOMOVOI — In Russian folklore, the guardian of the household, the household-spirit. Feminized in The Winter of the Witch as domovaya. In some sources, the domovoi had a wife, called the kikimora, but I felt that feminizing the name of the main household-guardian was more appropriate for a witch’s house.

DVOR — Dooryard. The space between outbuildings in the property of a highborn medieval Russian.

DVOROVOI — The dooryard-guardian of Russian folklore.

ECUMENICAL PATRIARCH — The supreme head of the Eastern Orthodox Church, based in Constantinople (modern Istanbul).

GAMAYUN — A black bird in Russian folklore that speaks prophecy, generally depicted as a bird with a woman’s head.

GER (YURT) — A portable round tent made of felt or skins and used by Mongol armies on the march. Generally they were taken down and put up each night, but the finest one, used by the Khan or the leader of the host, was often left intact and transported from place to place on a giant platform drawn by oxen.

GOLDEN HORDE — A Mongol khanate founded by Batu Khan in the twelfth century. It adopted Islam in the early fourteenth century, and at its peak ruled a large swath of what is now Eastern Europe, including Muscovy.

GOSPODIN — Form of respectful address to a male, more formal than the English “mister.” Might be translated as “lord.”

GOSUDAR — A form of address akin to “Your Majesty” or “Sovereign.”

GRAND PRINCE (VELIKIY KNYAZ) — The title of a ruler of a major principality, for example Moscow, Tver, or Smolensk, in medieval Russia. The title tsar did not come into use until Ivan the Terrible was crowned in 1547. Velikiy Knyaz is also often translated as “Grand Duke.”