The place was self-contained and almost self-supporting, with stores of food, good water, its own forge and leather shop, its own craftsmen and experts.
It took years for this place to reach this level of self sufficiency. 
mnli hypothesis: It took years for this place to reach this level of self sufficiency.  premise: The place was self-contained and almost self-supporting, with stores of food, good water, its own forge and leather shop, its own craftsmen and experts.