First, political power in Mayan societies, like that of the Olmecs who predated them, was centered in cities which ruled over the area around them. Some of the larger Mayan cities controlled surrounding, smaller cities, but the Maya civilization was not unified to the extent of the Aztecs. Scholars using ethnohistorical methods (i.e. studying Spanish descriptions of the Maya polities as well as archeological records) have concluded that their societies were highly stratified, with all political power flowing downward from a king, whose dynasty was associated with divinity. The king surrounded himself (literally, as Maya sites show) with lesser nobles and priests, who fulfilled bureaucratic and religious duties. Indeed, Mayan (and, perhaps to an even greater degree, Olmec) cities were not really commercial or residential centers but rather cultural, political, and religous centers. They were built as temple complexes rather than urban centers. Trade and other business was conducted in peripheral cities.