Some more data viz for you: this time, the number of moneyers operating at the mints of London and Southwark from c.973 to 1158.

coins, london, southwark, medieval
London and Southwark moneyers, c.973-1158

This visualisation is an output of my ongoing research project, PRMC-L: Post-Roman and Medieval Coin Finds from London. Funding for Phase 1 of this project has been generously provided by the British Numismatic Society’s John Casey Fund.