Slavkov ranks among the oldest well-preserved manors in Moravia. In the first half of the 13th century, a Teutonic Knights Commandery was built in the place of the present Baroque castle. Slavkov is first mentioned to be in their possession in 1237. Parts of the residential building and circular stair tower of the commandery are preserved under the northern tract of the Baroque castle and under one part of the castle courtyard. By the end of the 16th century, probably during the reign of Ulrich III of Kaunitz, a new Renaissance castle was erected on the older foundations with a four-winged groundplan, arcades and a huge prismatic tower.
The impulse for Baroque reconstruction of the Kaunitz Renaissance residence in Slavkov was laid by Dominik Ulrich Kaunitz at the end of the 17th century. This task of building a representative residence of the family in place of the inconvenient Renaissance building was entrusted to the Italian architect Domenik Martinelli of Lucca. Martinelli introduced his concept of the Baroque castle in the so-called Danube Baroque style in the 1680s. Besides the actual Baroque castle, he also included a modification and reconstruction of a greater part of the town with a new parish church. The actual building of the castle was designed in the shape of the letter U. Originally, the courtyard should have been ended by an entrance gate in the place of the present ground floor semi-circular stalls.
The construction of the castle started in the last years of the 17th century under the supervision of local bricklayer foremen and on infrequent inspections of Martinelli. The central – western wing with massively extended corners and haunches of both side wings was erected first. The western moat was arched over in its middle by a bridge with several stair levels. The retreating central forefront was emphasized in the first floor by a balcony opening to the garden from the central room of the 1st floor of the western wing. Martinelli’s typical interior solution consisted of two separate staircases and a rectangular vestibule segmented by huge ground floor columns. The designers of interior decorations were also Italian masters. The frescoes were painted by Andrea Lanzani who closely cooperated with the stucco master, Santino Bussi. Sculptures in the castle as well as in the park were done by Giovanni Giuliani.