British Museum

By the early fourth century A.D., Christian Chi-Rho symbols appeared with increasing frequency in Roman Britain—for example, on this mosaic uncovered in Hinton St. Mary, Dorset, and on the smallest triangular silver plaque in the previous photo. The plaque was originally affixed to a church wall in the small Cambridgeshire town of Water Newton; it was found with other valuable goods that had been buried there for safekeeping.