The army was one of those few institutions of the Hasmonean state of which relatively much is known. We owe this knowledge not so much to ample written sources as to the wealth of archaeological data. Their detailed interpretation was performed by I. Shatzman (1991), therefore here we confine ourselves to a brief outline of the Hasmonean military institutions.

John Hyrcanus' ascension to power in Judea may be considered the beginning of a new phase in the Hasmonean military because his reign saw events which led to significant changes in this field. John Hyrcanus, as the first among the Hasmoneans, introduced foreign mercenary troops to the Judean army. As we mentioned earlier, this came about most probably in connection with his participation in Antiochus VII's Parthian campaign and was necessitated by a need to safeguard his own interests in Judea while he was away. That decision, even if prompted by momentary circumstances, had a lasting effect. From then on, mercenaries became part of the Hasmoneans' armed forces, even though their presence in Judea aroused much vexation, for a number of reasons. The Judean ruler's part in the Parthian campaign afforded him insight into the working of the Seleucid army and an opportunity to gain experience in conducting a campaign away from native country and in adverse conditions.