[4] Even in Mughal times bankers were in the habit of placing their mark on the rim or even on the face of coins which passed through their hands. [5] _Guide to Taxila_, p. 117. Now the distinction between north and south which has just been drawn in tracing the history of this primitive coinage is very important; for this same distinction enables us to divide the remaining ancient and mediæval Indian coins down to the fourteenth century into two classes, northern and southern. The reason for this is that Northern India, during that period, was subjected to a series of foreign invasions; the indigenous coinages of the north were therefore continually being modified by foreign influences, which, with a few exceptions to be noted, left the coinages of the south untouched, to develop by slow stages on strictly Indian lines. The coins of the south will be described in a separate chapter. To return to Northern India: at the time of Alexander’s invasion the whole of North-Western India and the Panjāb was split up into a number of small states, some, like the important state of Taxila, ruled by a king, others governed by “aristocratic oligarchies.” Almost all the coins about to be dealt with are either of copper or brass, and the earliest of them were struck, doubtless, by the ruling authorities in these states. Even after their subjection to the great Maurya Emperors some of these states may have retained their coining rights, for it is a salient fact in the history of coins that coinage in the base metals in India and elsewhere has not, until quite recent times, been recognized, like coinage in gold and silver, as the exclusive privilege of the ruler. A striking example is afforded in the copper token money issued by private tradesmen in England during the eighteenth and early nineteenth centuries. On the break up of the Maurya Empire, at the close of the third century, a number of small independent kingdoms sprang into existence, and these proceeded to issue coins, some bearing evident traces of foreign influence, but on the whole following Indian models closely enough to be included here. No attempt can be made to deal with this class of coins exhaustively: a few typical examples only can be selected for description and illustration. The reader who wishes to pursue the subject further is referred for guidance to the Bibliography at the end of this book; and, since at present little attempt has been made to classify or examine these coins in any detail, fewer fields of research are likely to yield a richer reward to the patient student.