The Bernardine church and monastery was founded by the owner of the town, Prince Janusz Ostrożki, in 1614. The temple performed fortification functions, and the mighty bell tower of the church performed guarding and defensive functions.
In the eastern part of the monastery was a garden with fruit trees. In addition to the buildings within the monastery estate, he owned houses behind the fence. To the north was a wooden house – the so-called “Brewery”, which served as a brewery. On the south side, which leads to the city center, the church owned a hospital building for the elderly.
In the second half of the eighteenth century the church has several rococo altars. The students of the famous master of carving, the Lviv sculptor Ioan Pinzel, who is called the Ukrainian Michelangelo, took part in the creation of these altars.
In the dungeons of this cathedral were the burials of the noble families of Sangushki, Lubomyrsky, Illinsky, Frankovsky. The underground passage leading from the defensive moat to the crypts of the church was described by MV Gogol in the world-famous novel Taras Bulba.
In 1855 the church was consecrated to the Orthodox St. Nicholas Cathedral. Since 1993, the church houses St. Nicholas Cathedral. In 2000, the Mykolayiv Convent of the CPC was registered in the premises of the Lutsk Gate. On December 13, 2014, the Holy Synod of the UOC-KP approved changes to the statute in a new edition as the statute of the St. Nicholas Monastery in Dubno.
Currently, the architectural monument of national importance is used as a religious building and is a long-term lease of the Rivne Diocese of the Orthodox Church of Ukraine.