Series X is a continuum. This simple fact was missed by everyone, and numismatists divided these coins into three classes: VI, V, and IV. I have also divided Series X, and into even more (seven) design groups. The important difference is that the design groups are merely a division to understand how the designs were modified throughout the series. The series itself is used when examining the structure of the hoards and the patterns and techniques in coin-production.
Series X coins were minted at an undiscovered site on the east side of the River Rance. Their diffusion favours an easterly direction, probably away from the Roman advances into the area. It should be mentioned that I did not pay much attention to the structures of the smaller hoards and multiple finds. The main reason for this is that taking too few examples and dividing them by even three series can be misleading statistically. What could appear to be a significant percentage might turn out to be a single coin! I have found that 80 specimens is about the smallest number that can be used effectively
Throughout the expert system I have tried to include the most visible design elements for consideration. In Series X this is weakest in the description of the chariot drivers. Many of these drivers are either weakly struck or are off the coin. My book avoids much of this problem by having all of the dies illustrated, so while it might make some coins a little slower to identify by their design groups, it is still possible. Also, the expert system is not crippled by this feature when it comes to identifying coins by Series and the old Class.
The die engraver that created most of the dies for Series X was ever watchful of how his changes would affect the rest of the design. He was always working diligently to produce a better product. Whenever he found a plateau, he did not stay there but began again to explore the possibilities of his art. He was a professional, and most definitely my favourite of all of the designers.
Series X consists of my design Groups A to G inclusive. They were struck at a lower temperature than the coins of the other two series discussed here, accordingly, the dies were cut in low relief.