300 Years Young

This year marks three hundred years since the British artist, Sir James Thornhill completed his Baroque masterwork in the Painted Hall, making it a fitting moment to reflect on the remarkable story of its survival.

Designed and painted in two phases between 1707 and 1726, the walls and ceilings of the hall are filled with an extraordinary series of tableaus that seamlessly celebrate the achievements and ambitions of five successive monarchs and brings together a rich cast of historical, mythological and allegorical figures. Its effect can be overwhelming, but that is the point. An epic spectacle to stop you in your tracks.

Often described as Britain’s Sistine Chapel, Thornhill’s Painted Hall could not, on the surface, be more different from Michelangelo’s masterpiece. Michelangelo’s frescoes—water‑based pigments applied to wet plaster so that colour and surface fuse as they dry—are firmly rooted in religious iconography. Thornhill, by contrast, worked with oil paints on dry plaster, creating a far more secular scheme that, in part, pillories the absolute monarchy of the Catholic King Louis XIV of France.

The attributes that both share is that they are grand masterworks created by artists at the height of their powers, commissioned as instruments of propaganda to advance the political ambitions of their patrons. Restoring and preserving such works is more than an act of nostalgia; it is a way of deepening our understanding of where we come from. These artworks offer windows into past eras, revealing the evolution of artistic techniques, styles, and the cultural and societal values that shaped them.

Preserving the remarkable buildings and riverside grounds of the Old Royal Naval College has been the mission of the Greenwich Foundation – an independent charity – since it was established in 1997. Under our stewardship, the conservation of Thornhill’s masterpiece, one of Britain’s most extraordinary public artworks, continues to flourish.

Restoration – The Early Years

By 1733, just seven years after Thornhill completed the Painted Hall, poor ventilation and mildew were already taking their toll on the paintings, prompting the first of many restoration campaigns. Restoring an object typically means to ‘return it to an earlier condition,’ or to make it appear ‘like new.’ The choice of treatment or restoration approach lying firmly with the client or the restorer.

Until the 20th century, ‘restoration’ of the Painted Ceiling typically meant applying a new layer of varnish over the existing ones, which were darkened and dirtied by the environment, pollutants and smoke from tobacco and candles. The fresh varnish saturated the paint surface, instantly making the colours underneath appear brighter and more luminous. This approach was quick and effective, but temporary. Before long, the new varnish would itself discolour and darken, triggering repeated cycles of cleaning, revarnishing, and overpainting.

Their work, however well‑intentioned, lacked the scientific insight needed to safeguard the paintings for the long term.

A Move Towards Conservation

Between 1957-1960 the Conservation Department of the Ministry of Works, led by one of its chief restorers Westby Percival-Prescott embarked upon an ambitious programme of works in the Painted Hall. Their methods were more radical than conservators would undertake today, but at the time, they were considered state-of-the-art. The team approached the project with a new guiding philosophy: understand first, intervene carefully, protect for the future.

The work marked a turning point in the Painted Hall’s history. For the first time, conservation took priority over restoration, allowing the scientific analysis of the artworks to determine the treatment plan rather than rely on the restorer’s artistic interpretation and judgement.

For Percival‑Prescott’s team, working on scaffolding in close proximity to the ceilings and continually exposed to solvent fumes made the task extremely demanding. They removed up to fifteen layers of aged, darkened varnish, revealing details long obscured by grime. Once the surfaces were cleaned and retouched, they were coated with a layer of dammar resin varnish to ensure continued protection and stability.

A Modern Approach

Despite the Ministry of Works progressive efforts, by 2012 the Painted Hall’s walls and ceilings were once again showing clear signs of deterioration, with surface grime accumulating, paint beginning to flake and areas of blanching—a milky white veiling effect caused by light reacting with tiny cracks in the varnish.

A new investigation presented fresh opportunities to study the Painted Hall’s surfaces in depth, examining not only their condition but also the techniques used by the original artist, James Thornhill and the nature of later interventions and restorations. By applying non‑invasive methods such as infrared reflectography and ultraviolet light, conservators were able to reveal each underlying layer of under-drawing, retouching, and varnish.

The findings reshaped the conservation strategy. Research showed that the 1950s varnish was still stable and could remain in place, preventing any unnecessary intervention. Testing also demonstrated that gentle surface cleaning alone could achieve significant improvements without disturbing the existing varnish layers. Using conservation grade sponges with a mild alkaline solution—safe even for the paintings’ water‑sensitive surfaces—proved remarkably effective in lifting away accumulated dirt.

In total, conservators cleaned and revitalised 4,200 square metres of painted surfaces, securing and consolidating each loose flake of paint. They also applied a modern protective varnish to selected areas, ensuring long‑term stability and enhancing the visual clarity of the artworks.

Conservation specialists Paine and Stewart completed the work in two major phases. They treated the West Wall and Upper Hall between 2012 and 2013, then returned to restore the Lower Hall and Vestibule from 2016 to 2019, following a major fundraising campaign. The transformational £8.5 million project was delivered thanks to major support from the National Lottery Heritage Fund and the then‑named Department for Culture, Media and Sport, along with several leading charitable foundations and hundreds of supporters from around the world.

Safeguarding the Hall for future generations was equally central to the project. To achieve this, a series of environmental interventions — draft‑proofing, UV‑mitigating solar shades and a regulated conservation heating system—were implemented. These measures, developed using the latest technology, optimise the internal environment and ensure the long‑term preservation of the paintings.

Crucially, 80,000 visitors were able to watch the conservation work live as it progressed, from a specially built scaffold viewing platform in a groundbreaking act of transparency and public engagement. The project went on to receive the Museums + Heritage Award for Restoration/Conservation (2019) and the RIBA National Award (2019), among other accolades.

A Masterpiece for Future Generations

The Painted Hall we see today is the product of three hundred years of care preservation. From the heavy-handed efforts of the 18th century to the scientific precision advancements of the 1950s and the sensitive, evidence-based conservation of recent decades.

Visitors today experience the Painted Hall in conditions closer to Thornhill’s original vision than at any point since the early 18th century. It stands not only as a masterpiece of Baroque art, but as a testament to the evolving skills, ethics and dedication of the generations who have chosen to protect it.

This article was written by Simon Davies, Interpretation Officer for the Old Royal Naval College.

Works Referenced: The Painted Hall – Sir James Thornhill’s Masterpiece at Greenwich by Anya Lucas, Richard Johns, Sophie Stewart & Stephen Paine

Help preserve our legacy

As a heritage charity, the Painted Hall is open for the public to enjoy thanks to the generosity of our supporters. Please donate today to protect this Baroque masterpiece for future generations.