Well-preserved Medieval treasures have been unearthed from the greenish muck of a London cesspit. Up to 100 objects dating from the 14th and 15th centuries were found buried in a four-metre-deep pit underneath the Courtauld Institute of Art at Somerset House.

“It’s unusual to get excited about a cesspit, but this gargantuan piece of work is the only link we have found between medieval settlements on the Strand and the subsequent palace,” remarked Simon Thurley, the historian and former chief executive of English Heritage.

The remarkable discovery sheds new light on a poorly documented period in London’s history and its so-called “millionaire’s row.” Sumptuous mansions once lined the Strand, including a 15th-century palace called the Chester Inn, which had existed on the site where the Courtauld now stands.

Aside from an inaccurate drawing from 1543 by Anthonis van den Wyngaerde, “we have very few existing resources that we can use to understand this chapter of the Strand’s history,” explained the Museum of London Archaeology (Mola).

Mola researchers recovered intact pieces of pottery, drinking vessels, forks and other utensils, a ring, a pendant, and a belt buckle. An incredibly rare “Penn” floor tile was also uncovered – a typical ceramic design used to decorate palaces and monasteries.

“We just kept going deeper and deeper. To find something of that size – and all the finds that came out of it as well – is very unusual. Almost every time we put our mattocks in the ground, something else came up. That was great,” recalled Antonietta Lerz, a Mola senior archaeologist.

Many of these objects are in exceptional condition, despite visitors and residents of the Chester Inn discarding them into the courtyard cesspit hundreds of years ago. “When its contents have been fully analysed, we will begin to understand more about who built and used such an enormous pit. It’s an incredibly significant find,” declared Thurley.

Archaeologists were also amused by the “amazing coincidence” that, in the exact spot chosen to install new toilets for the Courtauld, they stumbled across a historic toilet. Senior archaeologist Lerz noted that the seemingly inconspicuous cesspit reveals “the less glamorous side of almost 500 years of luxury life alongside the Thames.”

Founded in 1932, the Courtauld has been redeveloping their teaching and Gallery spaces for the past year to create a more accessible environment. As a university that specialises in the history of art and conservation, this impressive hoard could not have been discovered underneath a more fitting London building.