In the year 1575 the count Adam von Dietrichstein assumed the sovereignty of Nikolsburg. As a true renaissance cavalier he stood in the service of the Austrian emperor. He was a close advisor and teacher of the future Bohemian king Rudolf II. He was also ambassador at the Spanish court, where he made the acquaintance with the court dame Margarita de Cardona, who became his wife. The most important member of the Dietrichstein family was the third son, Franz Seraph. Not only did he become bishop of Olmütz and cardinal laureate, but he also significantly shaped the city of Mikulov and its surroundings.
In accordance with his approach, architecture and landscape become united, and renaissance trends increasingly give way to the new baroque style. This all bestowed upon the city its unmistakable character, lasting to this day. In the splendid rooms of the castle one can find a theatre hall, a well-endowed library, and a room paying homage to the forefathers. The Loretto Chapel was constructed in the city, while on the Way of the Cross on Holy Hill the St. Sebastian Chapel was erected along with a bell tower.
After the Battle at White Hill (Bílá hora), Franz Seraph von Dietrichstein became the face of the restoration effort of the Catholic Church in Moravia. He pressed for a return to the Catholic faith and recruited Capuchins and Piarists to this end, who built monasteries and schools. Franz Seraph von Dietrichstein was the highest religious representative of Moravia. Mikulov at this time was a significant centre in the country.