According to legends Luchesk was founded in the 7th century. The first known documental reference is from the year 1085. The town was the capital of Halych-Volynia until the foundation of Volodymyr-Volynsky.
The town was founded around a wooden castle built by a local branch of the Rurik Dynasty. At certain times the stronghold was the capital of the duchy, but since there was no need for a fixed capital in medieval Europe, the town did not become an important centre of commerce or culture. In 1240 the nearby town was seized and looted by the Tatars, but the castle was not harmed. In 1321 George son of Lev, the last of the line, died in a battle with the forces of Gediminas, Grand Duke of Lithuania and the castle was seized by the Lithuanian forces. In 1349 the town was captured by the forces of Casimir III, but it was soon retaken by Lithuania.
During the period of Lithuanian rule the town began to prosper. Lubart, son of Gediminas, erected the Lubart's Castle as part of his fortification undertaking. Vytautas the Great founded the town itself by importing colonists (mostly Jews, Tatars, and Karaims). In 1427 he transferred the Catholic bishopric from Volodymyr-Volynskyi to Luchesk. Vytautas was the last monarch to use the title of "Duke of Volhynia" and to reside in Lubart's Castle. The town grew rapidly, and by the end of the 15th century there were 19 Orthodox and two Catholic churches. It was the seat of two Christian bishops, one Catholic and one Orthodox. Because of that the town was sometimes nicknamed the Volhynian Rome. The cross symbol of Lutsk is featured on the highest Lithuanian Presidential award, the Order of Vytautas the Great.
In 1429 Lutsk was the meeting place selected for a conference of monarchs hosted by Jogaila and Sophia of Halshany to deal with the Tartar threat. Among those invited were Sigismund, Holy Roman Emperor, Vasili II of Russia, the king of Denmark Eric of Pomerania, Grand Master of the Livonian Order Zisse
