alluvial soil - deposited by water
aeolian soil - loess - deposited by wind

tribe - a state designation for non-state peoples, may not necessarily
        apply to the bands of nomads

barbarians - state designation of border non-state people with which contact
	   and regular relations have been established
savages - state designation of non-state people with no regular
	contact/relations

acephalous society  - society that lacks political leaders or hierarchies.
	   State appointed somebody a chief, gave him gifts/privileges in
	   exchange for subduing his people and forming a hierarchy

raiding is uncertain and may kill the host, better to extract tribute or
	"protection fee"

barbarians were enlisted in the state's economy. 
- one of the major trade items were slaves: the barbarians raided the weaker tribes
- they collaborated in catching runaway slaves
- provided military service and suppressed native populations