When Grimes received a CBE for the discovery of the Temple of Mithras, he remarked that he was proud but wished that it had been in recognition for his work at Cripplegate - the discovery of the Mithraeum was "a fluke". His initial objective at Cripplegate was to understand more about the dating sequence of the city's defences. He soon discovered that the outline of the walls there represented the location of a 2nd-century fort. Over a 15-year period...