Zprávy památkové péče 2017, 77(4):401-416

The newly discovered medieval wall paintings in the Kunštát castle

Jan Beránek¹, Karel Maráz², Radim Štěpán³, David Zeman

¹ NPÚ, GnŘ

² Filozofická fakulta Masarykovy univerzity v Brně

³ NPÚ, ÚPS v Kroměříži, SZ Kunštát

One of the stages of the historical and architectural survey focused on the areas of the current third storey of the west wing, whose mass conceals the medieval walls of the fortification castle, revealed hewn stone corner brackets and tapered vault ribs in the present-day room no. 303 at the end of 2015, bearing witness to what was once a glorious Gothic space. Probes were followed by a restoration stratigraphic survey which revealed medieval wall figurative paintings under later layers of plaster. Work began on the overall heritage restoration of the room at the beginning of 2016 and ended with making the paintings accessible to the public in the first half of 2017.
The history of the Kunštát castle is inextricably linked with the Lords of Kunštát, the first known ancestor of whom is considered to be Gerhard of Zbraslavi († around 1241). We can assume that he received territory from Václav I upon which, during the 1260's, his youngest son Kuna I (first mentioned in 1250), the burgrave at the royal castles of Veveří and Vranov, the chamberlain of Brno, Marshal of Moravia and chamberlain of Olomouc, built the castle as his own representative family seat. Older historiography dated the castle's foundation to the late 1270's, to the time when Kuna first appears with the family name of Kunštát. Newer research on the foundation, on the other hand, moves the date to the first half of the 13th century. According to the results of an intensive historical and architectural survey that has taken place in the castle since 2005, we can say that the hitherto oldest proven building phase of the castle supports the period from 1264 to 1266. The most significant owner of the castle in the first half of the 14th century, when this mural cycle was created, was Gerhard of Kunštát, who twice held the office of chamberlain of Brno and Znojmo.
The paintings are located on the second floor of the medieval palace, adjacent to the western section of the fortification wall. The survey has conclusively proven that at its oldest stage the palace held at least three spaces. Probably until the end of the 13th century, the layout was on the ground floor and the first floor had a flat ceiling. On the level of the 1st floor, the horizontal communication was provided by the gallery which in the initial phase was mounted on wooden beams. The rooms with the wall paintings are directly associated with the ground plan of the southern part of the palace. More than half of the preserved medieval paintings are on all four walls. In the corners, hewn parts of a cross ribbed vault have been preserved, supported by brackets whose original profile can not be determined. The room is now vaulted with brick.
The survey allowed for the identification of four construction stages. The first phase includes the peripheral masonry and fragments of the ribbed vault. The masonry is demonstrably integrally related to the preserved fragments of the brackets and parts of the aforementioned vault. Restoration research has shown that the two-layer plaster on the quarrystone wall is primary. Both layers have the same material composition, and it is likely that the time gap between the construction of the 2nd floor of the castle and the origin of the paintings is very short. It can be assumed that the relevant part of the 2nd floor of the palace originated in a wider range during the first half of the 14th century. In the second phase, connected with the conversion of the castle to a chateau at the end of the 17th century, the ribbed vaulting was removed and replaced by today's unpreserved beam-ramp ceiling construction. The third phase can be combined with the reconstruction of the 2nd floor of the castle in the last decade of the 18th century, when the beam ceiling was replaced by the existing brick vaulting. The fourth phase was associated with a partial modification of the room after 1901, when the Baroque window niche in the western wall was modified to serve as an entrance to the newly established balcony.
The interdisciplinary restoration research was mainly focused on the wall painting, beginning mainly by non-invasive methods of exploration. The first part of the survey (non-invasive screening of the work) involved the detection of the structure of the painting examined in different spectral regions (UV, IR, XRF). colors (FC) were used for imaging. Based on the macroscopic survey and confrontation of analytical data from each image an analysis of the structure of the work was carried out, involving a study of the characteristic features of painter expression (drawing, underdrawing, modeling, secondary interventions, etc.) and an approximate analysis of the material composition. The results allowed for drawing documentation to be made and, at the end of the survey, a computer color reintegration of the paintings as well. This also allowed for the compilation of a stratigraphic overview of the construction of the work and the materials used. A separate part consisted of a comparative material survey of medieval and modern constructional binders which contributed to the evaluation of the individual building phases. Together with the historical and architectural survey and salvage archaeological research, surveys were made of selected structures, some being dated archaeometrically using dendrochronology and thermoluminescence. Experimental research of the masonry was also conducted using advanced non-invasive techniques - georadar, infrared thermography, and video scopes. The material characterization of the masonry was completed by a petrographic analysis of the stones. The masonry of the room is made up of a dark quarry stone with a slightly irregular face, stacked with an intention to correspond, and shows no noticeable structural inconsistency in the building development. The sandstone from which emerged the original stone articles were most likely made was mined near Kunštát.
The painting has been preserved at an estimated 50 % of its original whole. The changes made to the work can be divided into two groups. The first group is the preserved area of painting interrupted by secondary walls and newly made orifices, the removal of the gothic vaulting, the removal or disturbance of the medieval vaults, the raising of the floor level, and the creation of a stove niche. The second group of changes consists of damage to the plaster and color layers, especially dense chipping and static cracks.
The oldest plaster can be characterized as very high quality and compact. The substrate for the wall painting consists of a two-layered interlocking plaster system composed of a bottom and a top layer of plaster of varying strength separated by a lime coat, on the surface of which very fine dark animal hairs are visible. The plaster binder is based on dolomitic hydraulic lime with a specifically increased content of magnesium carbonate. Near-infrared (NIR) images contributed to a better orientation in the structure of the gradual construction of the painting. The brush drawing in this case fulfills two relatively different but closely related roles. In some parts it presents the basic compositional layout and is subsequently overlaid with the color layer, while in other places it functions as a full-fledged element of the painter's expression (morphology).
The spectrum of pigments used in the wall painting does not deviate from the historical context. The red pigments, representing the most varied group of substances, were identified as red clay, ferrite red, cinobr, minium, and another unspecified red dye. The blue pigments are represented by natural azure in blue and turquoise shades, and white pigments are represented by lead white and calcium carbonate. Other pigments identified include a carbon black of plant origin and yellow clay. The background of the scenes is made up of a lower black layer on which a transparent layer of blue azure was applied.
The construction of the work is stratigraphically simple, in which two color layers were applied in most cases. The absence of engraved artwork and daypieces, as well as the presence of a borderline on the surface of the plaster, indicate that the painting was executed on a dry mature plaster and excludes an initial fresco technique painting. A survey of the components of the colored layer revealed a binder based on dolomitic hydraulic lime blended with a protein component (casein). The technique can be assigned to a broader group of lime techniques based on the German designation Kalkmalerei.
The Gothic painting covers four walls and is composed of horizontal continuous bands of about 80 cm height, divided by a double band 17 cm wide. The continuous bands, filled with figural scenes and architecture, are not further divided by vertical strips, only with this function being filled in some places by a throne or architectural element. Part of the wall decoration consists of painted blocks of the entrance and window niches in the north and west walls. To date, no inscriptions have been preserved in the painting, the occurrence of which could be assumed, for example, in strips that divide the scenes. The painting can be characterized as profane with an emphasis on royal symbolism and battle scenes. Although there is no wider consensus on the date and theme of the paintings, it is now possible to place the work among extraordinary discoveries recently discovered.

Keywords: Kunštát castle, medieval wall paintings, historical and architectural survey, interdisciplinary restoration research

Published: December 1, 2017  Show citation