Michael Bloomberg, Founder of Bloomberg LP and Bloomberg Philanthropies, said: “As steward of this ancient site and artefacts, Bloomberg has embraced the City of London’s rich heritage. And as a company that is centered on communications – of data, information, news, and analysis – we are thrilled that Bloomberg has been at the core of a project that has provided so much new information about London’s first half-century.”

Made of wood, recesses in the rectangular tablets were originally filled with blackened beeswax, with text inscribed into the wax with styluses. Although the wax hasn’t survived, the writing occasionally went through the wax to mark the wood. As tablets were reused, in some cases several layers of text built up on the tablets, making them particularly challenging to decode.

Classicist and cursive Latin expert, Dr Roger Tomlin, deciphered and interpreted the tablets. Alongside photography with raking light and microscopic analysis, Roger used his encyclopaedic knowledge of Roman Britain and extensive experience of reading and reconstructing Roman incised texts from their fragmentary remains.

The preservation of the tablets is in itself remarkable, as wood rarely survives when buried in the ground. The wet mud of the Walbrook, a river that dominated the area in the Roman period but is now buried, stopped oxygen from decaying the wooden tablets, preserving them in excellent condition.

Once excavated, the fragile tablets were kept in water before MOLA conservators carefully cleaned them and, using a waxy substance, PEG, which replaced some of the water content, treated them before they were freeze-dried.

Over 700 artefacts from the Bloomberg excavation will be displayed in a public exhibition space that will sit within the new Bloomberg building, including the earliest-dated writing tablet from Britain. The London Mithraeum exhibition opens in autumn 2017.

The full research is published in Roman London’s first voices: writing tablets from the Bloomberg excavations, 2010–14, which is now free to download.

For media enquires about the Bloomberg writing tablets please contact media@mola.org.uk.