London has a long history of map making. We are lucky to have so many maps that document London’s development over the centuries, which often provide our archaeologists with vital clues about what to expect when we break ground on site, and help us to interpret what we find. However, because of changes in map making technology and convention, they are often considerably more difficult to use and navigate than modern maps.

We have set out to address this through our collaboration on Layers of London, a new digital platform which will allow visitors to peel back maps spanning 300 years of London’s history, to reveal the city changing over time. We have carefully georectified 9 of these maps - in other words, pulling them around in a Geographic Information System (GIS) so that they can be laid on top of an Ordnance Survey map.