Assumption Cathedral was built Mstislav Izyaslavich, Prince of Vladimir-Volynsky and, later Grand Prince of Kiev and was dedicated to the Assumption of the Blessed Virgin. The church's dome and vaults rest upon six cruciform piers, a structural solution similar to the one in the church of St. Cyril's Monastery in Kiev, suggesting that it was erected by builders from Kiev. The walls of the church had harmonious arches on pilasters with frescoes which were completed after the church's consecration in 1160. The church became the cathedral of the Diocese of Volhynia, which had been established in 992 as the first diocese in the area. To celebrate the 1000th anniversary of the diocese a memorial cross was erected near the cathedral.
The cathedral was the burial place of princes, boyars, and the bishops. Under the church there are 6 crypts with the tombs of two bishops and many noble persons. The crypt is also the burial place of Mstislav Izyaslavich. The tomb was ravaged by the hordes of Batu Khan but later it reconstructed.