In a contract signed on 30 October 1705, Prince Johann Adam Andreas I commissioned the artist Johann Michael Rottmayr to paint two soffits above the two grand staircases.

Recollection of Rottmayr’s frescos on the stairway ceilings faded after they were covered. It was only a 19th century description of the palace, that provided information on the iconography of the frescos and prompted speculations about surviving fragments under the oil paintings.

In order to make a realistic assessment of the scale of the missing portions and the damage caused by the breaking up of the surface detailed expert reports were commissioned; these also came to the conclusion that the project to uncover the frescos was feasible.

The pivotal issue in the discussion was the question of how the missing portions should be dealt with. The spectrum ranged from the neutral approaches of filling in the destroyed surfaces with the undercoat or with areas of colour, making the former content of these portions legible by reproducing the forms in grisaille, to full-blown reconstruction. After thorough consultation and discussion Prince Hans-Adam II decided to opt for total reconstruction, the only ap-proach that could recover the decorative value of the fresco for the overall experience of the original Baroque ensemble.

The precondition for the uncovering and restoration of this particular fresco, was a water colour sketch by Rottmayr preserved in a private collection in northern Italy. This sketch had long been thought to be connected with work the Salzburg Baroque painter was commissioned to carry out at Schönbrunn. Hellmut Lorenz was the first to posit a connection with the fresco in the East stairway in 1989 but was unable to supply positive proof at the time. His conjec-ture was finally confirmed when the fresco was uncovered in 2002. The sketch, which shows all the central figural groups as well as the lost portions, corresponds exactly with the fresco as it was executed “in situ”.

Work commenced on the East Stairway in the late summer of 2002. First all the covering layer of plaster was re-moved, then the protective meshwork taken down. After this the entire fresco was carefully cleaned. In the central section this involved removing quantities of cobwebs and some dust from the surface, while on the surfaces that had previously been overplastered a thin film of lime milk had to be removed which had initially made these portions appear somewhat cloudy.

Immediately after this cleaning process the free surfaces in the central section and the parts that had formerly been overplastered had already begun to resemble each other to a much closer degree. The condition of those parts of the fresco that had been preserved was especially satisfactory: in the almost untouched central section only a few tiny portions were missing. Protected from the damaging effects of light and having accumulated astoni-hingly little dust, the fresco had survived with the original radiance of its colours.

The next step undertaken by the restorers was to fill the holes then the smaller missing portions with lime mortar. The main problem here was to achieve the best possible match in the surface structure between the original and new por-tions. In the parts where there was more extensive loss the old layer of reeds – the base for the plaster – was re-moved and a new base for the undercoat made by attaching two layers of reeds laid at right angles to each other to the ceiling joists. The subsequent retouching took more than two years. Having gradually stabilised the condition of the fresco the conservator Herbert Schwaha now approached the last step: recreating the missing portions. These were drawn 1:1 on cartoons and the outlines then incised on the fresco layer of plaster. As is the case with the originals, these incisions in the plaster can still be clearly seen after the fresco has been painted. The restorator also used the traditional fresco technique of sketching the broad outlines of the composition onto the plaster in charcoal.

The sequence of stages also followed the traditional division of labour and historical techniques. First of all the missing sections of the quadratura, the architectural painting which draws the eye up into an imaginary celestial space, were completed. Only then did Herbert Schwaha start on the figural groups. If he was unable to complete a projected day’s work (giornata), the remaining unpainted section was cut out and relaid the next day. In the unfortunate case of a whole section proving unsuccessful in artistic terms, it was also removed again and the work repeated the following day.

This classic fresco technique, also used when the frescos were first painted, results in the formation of a silicate layer on the surface ensuring optimum binding of the pigments and producing an intensity of colour that is impossible to achieve in any other technique.

Measuring almost 220 square meters, the ceiling fresco in the East Stairway of the Liechtenstein summer palace represents a virtually complete classical pantheon. The composition includes three main groups which are placed a ninety-degree angles to one another taking into account the changing perspectives of the stairway. The title of the fresco – The Admittance of the Military Genius to Olympus – refers to the depiction in the central section in which a youth, symbolis-ing the military genius of the artist's patron, Prince Johann Adam Andreas I of Liechtenstein, is borne aloft by Minerva into the heaven of the gods. This apotheosis is symbolised by a genius offering a wreath of laurels and a palm spray to the youth; below this two putti play with the club of Hercules.

The fresco in the West Stairway depicts the battle of the giants and the gods. At the centre, borne aloft by an eagle, is Zeus, hurling a fistful of thunderbolts at the giants. Following events from behind a bank of clouds, as if sheltering behind a shield, are Mars, Venus, Mercury and Diana. Minerva takes a much more active part in the battle: she is protected not by clouds but a magnificent image of Medusa. Contrasting with the beautiful forms and faces of the gods are the bodies of the giants: bursting with vigour and entwined with one another they battle with the gods, hefting mighty boulders to hurl at them. The composition is magnificent: while that in the East Stairway is focused on the centre, here the figures move inwards from the edges towards the still empty centre.

In its coloration this stairway fresco is that much heavier than its companion piece on the east side of the palace; Rottmayr may have commenced his work here, still in thrall to an almost Mannerist palette. The pigments are thickly applied, as in oil painting, the medium in which the painter had developed his gifts. As a result, the fresco seems on the whole heavier than that in the East Stairway, where it has achieved a lightness and vivacity that already owes more to the Rococo.