was low; few city governments could afford to maintain a standing army for long. Simultaneously, internecine warfare created a floating population of the displaced and the exiled - someone has to lose. From this diaspora, professional mercenaries were recruited in times of conflict, largely replacing the less-organized, more-motivated hoplites.
Macedon's army was professional and permanent. Surviving a series of civil wars and Greek incursions into Macedon early in his reign, Philip understood the value of such an arrangement. As a matter of loyalty, Macedonian nobles still offered the services of themselves and their tribesmen, but the core of Philip's army would always be full-time men in his pay, loyal to him - and as king he had control of the silver mines with which to pay them. It must be noted that he was not despotic about this arrangement. Macedonian kings were not democratic-minded, but they did rule with respect to certain customary rights of the Macedonian people, for example:
There is some evidence suggesting that the Macedonian people, or army (for in a state like that of the Macedonians the two are almost indistinguishable), possessed a traditional right on the death of a king to appoint (not merely to acclaim) his successor.
Macedon was no doubt an autocrat-dominated oligarchy, with "leading families" comprising the inner circle of power-holding nobility. Still, as befits a people who value horses and live closely to nature in a non-farming society, the "nobility" itself was a more democratically numerous and physically-active class than the term generally implies to the modern reader. Theirs was not an hierarchic, feudal system as we have come to know those terms. There was a streak of independence running through the typical Macedonian noble-cum-soldier that any intelligent commander would have to respect. As assassination or civil war was the rule rather than the exception in matters of Macedon...