A huge panorama of London as it was at the end of the Napoleonic wars has gone on display at the Museum of London. The watercolour over pencil work was painted by Pierre Prévost in 1815. As huge as this panorama is, it is just a fraction of what it was meant to be. It’s a preparatory study for a panorama more than 100 feet wide. Prévost successfully completed the behemoth, the epitome of his work as a panoramist, but it is now lost.

Panoramas were all the rage starting in the late 18th century. The term was coined by artist Robert Barker in 1787 when he had the idea to create a 360° view of a city in detailed perspective. Viewers would stand in the center of a custom-built rotunda and immerse themselves in the vista of a distant city. Barker built his first rotunda and panorama in 1793 and by 1800 they had taken off like wildfire.

Prévost was one of the premiere artists of the form. His first panorama, View of Paris from the Tuileries, was created in 1799. Many others followed, including views of Amsterdam, Athens and Jerusalem. He went to London to make a panorama of the city in 1802 (also lost), during the brief break in the Napoleonic wars after the Piece of Amiens, and then returned after Waterloo in 1815 to create the view from Westminster Abbey of which this prep is all that remains.

Painted from the bell tower of St Margaret’s church, right next to Westminster Abbey, the view encompasses the Abbey, its graveyard, the Middlesex Guildhall (then only 10 years old), the medieval Houses of Parliament which would be destroyed in a catastrophic fire in 1834, St. James’ Park, the Palace of Whitehall’s Banqueting House, the future Trafalgar Square and the church of St. Martin-in-the-Fields. Prévost captures not just London’s architecture, but its lifeblood as well. There are street scenes of people going about their business — carts carrying goods, shops, a factory — and views of the bustling shipping trade on the Thames.

The finished panorama was exhibited in a rotunda in Paris. That the preparatory drawing has survived is remarkable. Highly finished, detailed, scale sketches were necessary to create so enormous a finished painting, but only one other is known from the many panoramas in Prévost’s oeuvre, a view of Constantinople now in the Louvre.

It was recently rediscovered at sold at auction at Sotheby’s on July 4th, 2018, for 250,000 ($330,000). The Museum of London was able to acquire it with the support of the Art Fund, the Aldama Foundation and several private donors. Since then it has been conserved by museum experts and is on display for the first time as of today.

The photograph cannot do this work justice because it’s so much wider than it is high, but thankfully the Museum of London has create a neat video that scrolls over the panorama with key sites labelled.