From the 8th to the 3rd centuries BC, every household or extended family tried to make enough products to survive for a year. They forecasted bad harvests and stocked for the next year and held small pastures. As Aristotle states in “Politics”:
“Everyone would agree in praising the territory which is most entirely selfsufficing; and that must be the territory which is all-producing, for to have all things and to want nothing is sufficiency. In size and extent it should be such as may enable the inhabitants to live at once temperately and liberally in the enjoyment of leisure. […] As to the position of the city, if we could have what we wish, it should be well situated in regard both to sea and land. This then is one principle, that it should be a convenient center for the protection of the whole country: the other is, that it should be suitable for receiving the fruits of the soil, and also for the bringing in of timber and any other products that are easily transported by sea.”
Its important to stress that autarky didn’t result to isolationism, and in fact served as an impetus for trade…
Archaeology has shown that cultivation and stock-breeding hadn’t evolved much in antiquity. Yet mining evolved rapidly in the Hellenistic times, following the death of Alexander the Great. Land cultivation provided a steady and certain income for both the land owners and the city, through revenues and publicly owned land.
But some cities didn’t have the space for agricultural activities, mines, quarries, or slaves to trade. A great example was Delos.
Delos was a small rocky island, in the middle of the Aegean Arhipelagos. Yet it managed to achieve great economic success. Its secret lays on the myth that Delos was the place where Apollo and his sister Artemis were born. The Temple was one of the holiest at its times, thus the island was never threatened by pirates. Soon, wealthy people and cities made dedications to the Gods, later on kings of the Hellenistic period joined in, competing one another.