Restoration of the façade, the bell tower and the Chapel of  St. Roch
Cathedral of St. Mark, Korcula, Croatia

The Church
The Cathedral of St. Mark was built in the early 15th century in an ornate Gothic style by Korcula builders using local limestone from the nearby islands of Vrnik and Kamenjak. Three apses remain of the previous building. The first architect was Hranic Dragoševic from Korcula, followed by Ratko Ivancic and Jacopo Correr from Trani. Towards the end of the 15th century, when the cathedral was completed, the eminent architect Marko Andrijic (b. 1507) worked on the building, sculpting the central rose window, the frieze on the tympanum, and building the crowning of the bell tower.
In 1525 construction began on the chapel of St. Roch.
The church’s façade was built with smooth stone blocks and does not follow the arrangement of the internal naves. The sculptural decoration is concentrated on the tympanum, rose window and central door. The door is the work of the Lombardian master Bonino da Milano (he also designed the door of the Cathedral of Šibenik and the Gothic chapels in the Cathedral of Split, the former Mausoleum of Diocletian, restored by Venetian Heritage in 2003). Written in capital Roman letters on the door’s architrave is: “D.O.M.B.M. V.DO Q MARCO EVANG. SACRVM” (deo optimo maximo beatae mariae virgini divoque marco evangelistae sacrum).
Inside the lunette is a statue of the patron saint of the cathedral. He is wearing vestments and sitting on a cushion-covered throne, in the act of blessing with his right hand. His left hand holds his Gospel. According to Milan Prelog in his article “Dalmatinski opus Bonino da Milano” (“The Dalmatian Works of Bonino da Milano”), Bonino is first mentioned in Dalmatia in 1412 in relation to the construction of this cathedral in Kurcola. Proper scholarly attention has never been given to this fact. Signs of his work in the cathedral have never been looked for, though the text of a notary deed makes it clear that Bonino played a significant role in building the church. On August 25, 1412 it was agreed that a local stonemason named Toma Zubovic would work to complete the plan given to him by Bonino.
In 1417, Bonino’s name it’s recorded for the first time in Dubrovnik. In 1417 and 1418, he was mentioned in the building documents for the church of St. Biagio, which was destroyed by an earthquake in 1667. Later it is listed that Bonino was still in Dubrovnik in December 1422 when he received the commission to build the stone gallery in the Rector’s Palace, the governmental seat of the Republic of Ragusa. The next mention of Bonino is for the construction of the St. Doimo chapel in the cathedral of Split in 1427, although he had already been working in the city for several years. The last archival document on Bonino is from Šibenik, where he worked in 1429. After analyzing the door of the cathedral of Šibenik, it is easy to see Bonino’s style on the door of the cathedral of St. Mark in Korcula, in its figurative elements as well as its decorative and architectural ones. The Korcula door has more archaisms than the ones in Šibenik, particularly in the outer cornice where we see typical Romanesque motifs such as lions tearing their prey, crouching figures of Adam and Eve and elegant bows on the columns.
On the door, despite these 14th-century style elements, typical features of the elaborate Gothic style are evident like the background of the lunette perforated with extended, quatrefoil geometric patterns. In the figure of St. Mark on the lunette, we can see all of the formal details featured in the figures of saints made by Bonino. The lunette relief of the side door in Korcula dedicated to St. James, is also by Bonino.
Above the main door there is a large rose window by the sculptor Marko Andrijic. The rose window’s outer frame was decorated with four grotesque masks. In the center of the rose window there are eighteen small columns in the form of sun rays, which terminate in small trefoil arches and round quatrefoils. The final part of the façade is lavishly sculpted with floral and architectural motifs. On the top of the tympanum there is the bust of a young man in a shirt in the style of the period with long hair and a diadem on his head.
The lower part is made of blocks of solid stone interrupted by windows on the first and second floor. The top of the bell tower is decorated with a covered loggia and a dome crowned with a lantern. A cornice decorated with vertical leaves divides the levels. On the first level are Romanesque style windows, the clock, and a circular opening on which there is a sphere that shows lunar changes. On the second level there are two double pointed arch openings, unlike those on the south side that have straight peaks. On the corners of this level are small heads of lions and people.
St. Mark’s lion is sculpted in relief on the front of the ba- lustrade. On the north side of the bell tower are the coat of arms of the bishop Tommaso Malumbra. On the opposite side is the coat of arms of Prince Nicola Mule, and those of Prince Zorzi Viaro is on the southern part. The final part of the bell tower consists of an octagonal covered loggia, small dome, and lantern, also octagonal in shape. The loggia has eight pilasters made of groups of half pilasters. The dome is separated into eight parts by stone bearing ribs, joined with slabs of stone. Marko Andrijic was extraordinarily important in the history of Dalmatian art and, in particular, architecture. His major contributions to his city’s cathedral were the ciborium over the high altar and the top of the bell tower. His last works, including the bell tower of the Franciscan church in Hvar, became models for the bell towers of Dalmatian Renaissance and Baroque churches. Construction on the bell tower of the church of Korcula continued for the entire first half of the 15th century.

The Restoration
The stone surface was partially covered by black crusts of varying thicknesses. Particularly in the areas not affected by the solvent effect of rainwater (on the internal part of the columns, the undercuts of the capitals, and especially in the most protected part of the lunette and all the sculpted parts of the tympanum’s cornice). A widespread yellowish patina was deemed fitting and was kept. The old stuccoes had lost their adhesiveness and compactness. Many widespread gaps were evident, filled in with mortar that was unsuitable in color and composition. Some of the mortars were cement-based and probably done during previous maintenance (particularly on the lower part of the door). All the cement based additions were removed and replaced by suitable mortars.
The overall condition of the upper part of the façade was very poor.
All of the tympanum’s stone elements were disconnected. The iron elements, which served as anchors between the blocks, and the underlying structure were
almost completely oxidized, and in some places no longer remained. In addition, their oxidization caused the iron to expand, making many of the stone blocks crack. During the restoration, the decision was made to completely dismantle the upper architectural row of the face to remove all iron elements completely and replace them with new stainless steel pins and braces. The scaffolding was modified in order to withstand the weight from the disassembly of the tympanum’s stone blocks. Several stone plugs were also made to fill in the largest gaps in the stone surface.

The Chapel of St. Roch
The chapel of St. Roch was built in 1525 next to the northern nave of the Cathedral by an architect, Marko Milic Pavovlic, as a votive offering from the residents of Korcula who were victims of a severe plague at the time.
The façade is made with smooth, local limestone blocks and is in line with the Cathedral’s façade and bell tower. Two small rectangular windows with pointed arches are on the sides of the central door. The door is surmounted by a semicircular lunette holding the statue of the chapel’s patron saint. The statue’s proportions may be too large for the lunette. On the top of the lunette is the bust of the Virgin with Child. On the sides are two noble coats of arms sculpted in relief. The façade terminates with an elaborately sculpted cornice with floral motifs.

The Restoration
The decorated cornice was covered with a clinging layer of microorganisms, most likely moss and cyanobacteria.
These mosses attach to porous materials and deteriorated the stone’s carbonatic substratum by producing organic acids. Their patinas vary in color, length, and thickness (black or gray for cyanobacteria). Unfortunately the stone surface had been severely damaged by this organic crust and is now irregular and very porous. The wall showed no serious static problems.
The black crust was only visible in some areas under the sculptures and reliefs.
Lichen had spread throughout the stone surface. Some stone blocks had a nice natural ocher patina, which was kept. There was a profusion of some weeds like pellitory, whose roots slipped between the stone blocks and caused water to leak in the building. Most of the stuccoes were not original, but cement-based and non-adhering.
The door had areas with black crusts of different thicknesses on the underarch, on the back of the saint and the undercuts in general. The statue of the Virgin and the side coats of arms surfaces were corroded by rainwater. They were covered with gray microorganisms. The saint’s staff was seriously damaged in the past and the upper part was lost. There was a broken copper pin inside. Some cracks were visible on the legs of the statue of St. Roch, mainly at his knees, which was poorly plastered with gesso during an undocumented restoration. It was likely during the same period that the cement-based plaster was applied on the background of the lunette, which is now removed and replaced with limestone and stone powdered plaster.