All frescos had to be freed from the dust of centuries and are now resplendent in their original intensity of colour.

Pozzo’s ceiling fresco in the Hercules Hall and Rottmayr’s frescos in the rooms of the ground floor were found to be in a remarkably unimpaired condition and effectively only needed a few loose parts fixing and a thorough cleaning.

Only Rottmayr’s stucco-framed ceiling frescos in the Sala Terrena had suffered acutely from 19th century restorations and some completely new additions by Karl Geyger in the 20th century. These pictures required extensive work to ensure the complete reconstruction of the overall baroque ensemble.

More serious problems arose with the frescos in the Sala Terrena on the ground floor that had originally been open to the elements and thus exposed to climatic variations. Despite their state, the restorers were again able to achieve a harmonious overall condition, integrating the frescos into the baroque ensemble.

The oil paintings presented the restorers with bigger problems. While the pictures by the Bolognese artist Marcantonio Franceschini were in reasonably good condition, the paintings by the Venetian Antonio Bellucci had not fared so well. Following their transfer to Rossau from the City Palace on Bankgasse in the 19th century, they had been the subject of numerous format modifications, additions, retouches and outright overpaintings. Moreover, all the paintings had subsequently been coated with a thick varnish which had turned quite yellow with age.

The object of the restoration was to find solutions to all the paintings’ technical problems — loose pieces of paint, water damage and earlier restorations — and to carefully thin the layer of varnish to achieve a uniform condition that would allow the paintings to be seen in their original vividness.

During the restoration, considerable attention was paid to preserving the remaining varnish and all coatings, in order both to avoid damaging the original substance and to preserve something of the existing patina.

Only in the case of two paintings by Bellucci were the later additions removed and the original format restored. These additions, which on their rear sides show fragments of a leopard and of a portrait, obviously came from pictures in the gallery which were cut up and then “recycled”.

Unlike other Viennese interior decoration schemes, the stuccowork of the Garden Palace was not redone during the 19th century in order to meet the representative demands of Historicism. The work executed by Santino Bussi remained in its original condition.

At the outset of restoration work, the stucco lacked its original vividness due to the addition of later layers. These were carefully removed. Uniformity of appearance was achieved by retouching with a limewash glaze which, by virtue of its transparency, makes the original characteristics of the lime stucco visible once more.

The composition has regained its distinctness particularly where the three-dimensional stuccowork merges with the linear patterning on the background surface. The contrast between the plastic sections, relief and patterning highlights to best effect the intensity of the forms and, hence, one of the main attributes of this stuccowork.

Both the palace and the gardens used to be ornamented by an extensive collection of sculptures by Giovanni Giuliani, almost all of which have been lost. Of the garden sculptures, only a few vases and two monumental statues have been preserved. The original Giuliani sculptures on the outbuildings were replaced by copies decades ago.

The vases and the sculptures in the gardens suffered extreme salt corrosion and their surfaces were almost completely destroyed. They originally had a smooth stuccolustro coating, which was supposed to mimic precious marble. Before the oil-based colour coating could be applied, the sculptors had to demineralise the objects and carefully replace all the missing parts.

Two important sculptures by Giovanni Giuliani for the Sala Terrena, made for Prince Johann Adam Andreas I based on models of Soldani, had also disappeared but have now returned to the palace.

Several individual parts were missing from the sculptures, but they have been recreated with the help of photographs. On account of the high degree of salt corrosion, it was again decided to apply an oil-based coating which, incidentally, corresponds to the original condition.

Giuliani’s vases inside the palace were beset by similar problems. Their external ornamentation, in particular, had suffered a loss of form, and this had to be improved upon.

In order to be able to even contemplate returning the artworks — currently stored under ideal conditions in the repositories of the castle in Vaduz — the entire palace was brought up to the highest standards of modern museum security and climate control. The insufficient number of utilitarian rooms was also increased, with extra space being created in a completely new basement floor beneath the Sala Terrena.

The stone elements of the Sala Terrena, originally covered with a lime coating before being stripped to the bare stone and reworked in the 19th century, were given back their historic lime surface. The floor covering was also restored according to historical documentation.

When the gallery premises were remodelled at the beginning of the 20th century, the Liechtenstein family archives were moved to the rooms of the Ladies’ Apartment, where they remained until 2001. For this usage as a family archive, steel shelves were installed and — as with the library in the Gentlemen’s Apartment — the floor was raised by about a metre. These changes left behind nothing of the original room proportions or the original quality of the decor.

In the course of the restoration process, the floors of the former Ladies’ Apartment were brought back to their original level, allowing these rooms and the restored Rottmayr frescos to be experienced in their original spatial proportions, doing full justice to the monumentality of the Roman Baroque.

The rooms were also refitted with their historic floor coverings, originally “marble tiles from Kehlheim”, and will be used in future for temporary exhibitions and events.

When the Majoratspalais in Herrengasse was vacated by the Princely Family at the end of the 19th century, the library and its furnishings were moved to the galley premises in Rossau. The rooms of the Gentlemen’s Apartment were converted and modified for this purpose, and the bookshelves themselves were also adapted to fit into their new environment. A photograph taken at the time shows the historic elements and the new additions, as yet without polychromy. This allows us to be fairly sure which parts were added at that time.

The varnish protecting the surfaces had yellowed considerably and had to be cleaned, meaning, as in the case of the paintings, the original colours can now be much better seen. The gilt surfaces were cleaned and their gaps filled out. Their soft shimmer, together with the re-installed classicistic chandeliers and wall lighting fixtures with their silk shades, give these rooms their special atmosphere.

The rooms on the first floor (Piano Nobile), which had been painted white for the past few decades, have been returned to their original colours and provide a worthy setting for the works of art to be exhibited there.

A great cause of delight was the rediscovery of the historic parquet flooring from the late 18th century, laid at the time the gallery moved into the building. The object of extensive restoration work, it likewise makes an important contribution to the colour composition and the desired atmospheric itensity of the premises.