A 10-year programme to restore all the gilded carving that embellishes the chapels and nave at St John’s Co-Cathedral has been concluded with the restoration of the chapels of France, Provence and Anglo Bavaria. It also included the res­toration of several canvas paintings and marble monuments.

The project was financed by St John’s Co-Cathedral Foundation, which is committed to the restoration of the church and its sustainable use. The foundation was assisted by the Cicada Foundation for Art and Education which sponsored the cost of the works in the chapel of Provence.

The conservation policy adopted for the restoration of the chapels emphasised on long-term stabilisation. In this regard, the study of the history of the building and its works of art assisted us in identifying past interventions and additions.

The decorative history of the chapel of France, dedicated to the conversion of St Paul, started in 1614 under the patronage of the French Grand Master Alof de Wignacourt. Extensive embellishment continued in 1664, when according to a contract of service, the procurators of the langue wanted to have the most beautiful chapel in the church.

They commissioned Giuseppe Faudali and Giovanni Battista Menville to build a new altar and carve the walls. Antonio Foti was then commissioned to hammer 240 gold Spanish doubloons necessary to gild the chapel. This is the only chapel were the background of the dome is also gilded; all the others are painted. The dome was carved and gilded with the French fleurs-de-lys, and exotic gilded caryatids hold the segments together.

The procurators, determined to outshine the other sacred spaces, ordered yet another new altar in 1666, this time designed by the Maltese sculptor Melchiorre Gafà. The chapel was completed in 1668 with Mattia Preti’s depiction of the dramatic Conversion of St Paul for its altarpiece.

The lunette-shaped spaces above the walls were fitted with paintings depicting The Shipwreck of St Paul in Malta and The Beheading of St Paul in Rome. An artist, Kilian F., perhaps an initial of his first name, or ‘F’ for fecit, signed these works. Little is known about Kilian and his activity in Malta.

The history of the decoration of this chapel continued in 1838 when the wall carvings of the chapel were remodelled by the sculptor Salvatore Dimech under the direction of the artist Giuseppe Hyzler. He was a follower of the Nazarenes, a movement that aspired to reform Christian art and cleanse it from the excesses of baroque art.

The soft globigerina limestone of the church is ideal for intricate stone carvings, but its softness and porosity makes it vulnerable to natural deterioration

At the chapel of France, this led to the carvings of the walls being simplified and the altar replaced, while the funerary monument of Grand Master Emmanuel de Rohan was remodelled. This type of intervention was planned for the rest of the church, but was thankfully abandoned after letters in the newspapers criticised the attempt.

The chapel of the Langue of Provence was also restored in the present project. As in all other chapels, the centre of the dome carries the coat-of-arms of Grand Master Jean de la Cassière who had ordered the church of St John to be built. This coat-of-arms serves as a seal of de la Cassière’s authorship of this church.

Records show that in March 1646, the procurators of the chapel of the Langue of Auvergne were drafting a contract for a new altar for their chapel. In it they specifically requested that the style of the altar be similar to that of Provence, making it possible that Antonio Garsin, the designer of the Auvergne altar, also did this one.

This makes the Provence altar one of the earliest baroque altars installed in the church. Its design is typical of early 17th-century baroque; its set of twin columns on either side are influenced by Bernini’s Solomonic columns designed for the baldachin at St Peter’s Basilica in Rome in the 1630s.

The altar painting depicts The Archangel St Michael. The work is a faithful copy of Guido Reni’s painting in the church of Santa Maria della Concezione in Rome. It arrived in Malta in 1653, a gift of Commander Fra Alberto Orsi to the Provencal Grand Master Jean Paul Lascaris, who requested the painting to hang in the chapel of his langue.

Restoration can also assist attributions and dating works, as in the case of the lunette painting depicting The Apparition of St Michael on Mount Gargano. Cleaning revealed a detail from Commander Fra Jean Jacque de Verdelin’s coat-of-arms dating the work to around 1661 and 1663, forming part of the embellishment he sponsored for the chapel.

The historical account of Count Saverio Marchese in his Uomini Illustri di Malta, based on Fra Bartolomeo Mifsud writing around 1760, states that this painting and that of St Sebastian in the chapel of Auvergne are by Fra Lucas Garnier, a knight attached to the Langue of France. It also seems natural that the French knights both of Provence and Auvergne wanted to engage a French artist. He received his artistic training at the prestigious Roman Academy of St Luke in 1636.

During restoration, the study of the chromatic values, quality of the paint layer, and the form of deterioration both paintings sustained showed that they were similar, thus strengthening the attribution.

The dome carvings consist of eight seraphim angels accompanying 16 little angels holding black birds, and another eight angels in the spandrels. Angels are the guardians of the heavens and the numerous amount in this chapel give it a unique heavenly character.

On the walls, black birds, a motif from Verdelin’s coat-of-arms, rest on golden vine branches nibbling at its fruit, while a profusion of weapons symbolic of the military role of the Order cover the other surfaces. The laborious task of gilding the chapels was carried out by Michele Pandova, while the gold leaf was hammered from Spanish doubloons by Foti.

The restoration project was designed to check deterioration and enhance the aesthetic qualities of these sacred spaces.

Over the years the carvings had collected dust and candle soot. As a result, the gold lost its brilliance and caused the carvings to appear blunt and uninteresting. Dust and soot had also accumulated on the marble monuments rendering the once brilliant white marble grey and dull.

The varnish of the paintings had oxidised and darkened, masking the original colours. It also made the composition difficult to read. Collectively these conditions had a severe impact on the chapels’ aesthetic appeal.

The soft globigerina limestone of the church is ideal for intricate stone carvings, but its softness and porosity makes it vulnerable to natural deterioration. In all the chapels, the upper courses absorbed rain water that had filtered in from the domes, while the lower courses were affected by rising damp as a result of capillerisation.

The deterioration of the chapels was typical damage induced by the crystallisation of soluble salts inside the porous stone walls. The salts crystallised at different heights depending on their solubility and varying ambient conditions caused by seasonal changes.

For example, carbonates being the most soluble crystallised at the upper levels. The lower strata of the walls also suffered deterioration caused by rising damp through the stone courses. The resulting capillerisation of nitrates and sulphates formed efflorescence and crusts, causing the loss of the gilding layer, while leaving a noticeable white salt deposit on the surface.

The expansion of salt crystals caused by the repeated fluctuations of relative humidity in the church was the main cause of damage, including micro-decohension and disintegration of the stone structure. In turn, this caused detachments and losses in the gilt layer and lifting in the paint layer, blooming, staining and encrustations.

Another phenomenon caused by the movement of soluble salts was extensive blanching on the gilt and painted surface of the walls.

The restoration project consisted of diagnostic tests of the paint and gilt layers to identify the original materials and methods of application used in the 17th century.

According to the results, the appropriate metho­dology for the restoration was planned.

The initial phase of the restoration consisted of preservation measures to consolidate detached paint and gilded layers by injecting specific resin-based adhesives.

This was followed by removing the large quantities of superficial dust by vacuum suction and soft brushes.

The gilded carvings and painted areas were cleaned with various methods depending on the original technique used. Often, deionised water was sufficient to achieve good results.

The exceptions was the layer of linseed oil applied on the lower courses, which was removed using alkaline solutions, and stubborn encrustations were removed with diluted chemical solutions.

Particular attention was given to areas affected by salts and nitrates. These surfaces were treated with poultices desalinating and cleansing the stone surfaces.

The next step was to repair open mortar joints and minor cracks with a hydraulic lime-based mortar known for its compatibility with limestone. Missing parts of the carvings were reconstructed with cellulose pulp because its composition is light and suitable for reconstructions. Its properties also control humidity absorption from the wall, sustaining the repairs more efficiently.

Regilding with 24-carat gold leaf imported from Florence was carried out with the two different techniques according to the original methods used in the 17th century.

In the oil mordant gilding technique the stone carvings were prepared with a wash of red lime-based paint to enhance the colour of the gold leaf. The oil mordant was then applied and the gold leaf transferred to the carvings.

Regilding with 24-carat gold leaf imported from Florence was carried out with the two different techniques according to the original methods used in the 17th century

In areas that had been gilded with water gilding, known as the bolo technique, two layers of bolo made from red clay were applied and the gold leaf fixed with rabbit skin glue.

The damaged area that had been decorated with wall painting was integrated using water-based paints.

The canvas paintings were brought down from their position and transferred to the temporary laboratory set up within the co-cathedral. Diagnostic tests using non-invasive methods were carried out and the paintings documented.

Successive layers of oxidised varnish had affected the aesthetic appearance and advanced craquelure was pulling away at the paint and ground layers and had led to some losses of the paint layer.

A series of cleaning tests were carried out to find the appropriate methodology to clean the paintings, as each case is different. For these paintings, acetone was used to lift the layers of oxidised varnish. Some over-painting in The Conversion of St Paul was removed since they were made by a previous restoration attempt. Small losses in the paint layer were filled and retouched with varnish colours using a reversible method that is easily identified from the original. The original wooden stretchers were treated for infestation and strengthened.

The linings that had been applied in a previous restoration attempt were removed and strip lining was applied to the edges of the canvas that had become frail or had deteriorated with the passage of time.

For The Conversion of St Paul the original wooden frame was retained and an innovative spring stretch system was designed using stainless steel materials attached to the frame. The paintings were then varnished and placed back in their original positions in the chapels, concluding the restoration programme.

There are few time capsules from the past that capture our imagination. The Acropolis, Pompeii and Hagia Sophia are among the few that immediately spring to mind. St John’s Co-Cathedral is there with them. The conventual church provides one of the most complex snapshots of a unique phenomenon.

The Order of St John projected this church as a special place that captures all the values that the knights stood for. Embedded deeply in the artistic splendour of St John’s is a remarkable history of latter-day crusaders who were aware that the age to which they belonged would come to an end.

The restoration of St John’s artistic splendour is a celebration of its remarkable artistic importance and its special space in history.

As a special place it deserves the care and conservation that modern science can provide.

St John’s is one of those places where the arts, religion, science and thought collide with such spectacular effect. It is an effect which transcends generations.

Cynthia de Giorgio is curator at St John’s Co-Cathedral.