Some 42 silver Northumbrian coins were analyzed by x-ray fluorescence (XRF) and energy dispersive analysis in a scanning electron microscope. The study aimed to investigate the chronology of the series and the relationship between specific issues. The results indicate that the Aldfrith coin examined should be attributed to Aldfrith of Northumbria rather than a later monarch. The fineness of the series seems to fall in a series of stages, 3:1, 2:1, and 1: 1 or lower. There is no evidence that coins were produced at more than one workshop. -- AATA