Explain the Economic and Military Role of the Perioeci and Helots

Many people forget or undermine the importance of the perioeci and the helots in their study of Sparta, dismissing both groups as only slaves or inferiors that later overthrew the Spartiates. In truth, the perioeci and the helots both played an important role in the economic and military aspects of Spartan society, and contributed much to Sparta's fame and military prowess.
For the Spartan citizens, the other aspects of their life were left to the perioeci and the helots. Plutarch describes the perioeci as the "dwellers round about", a substantial group of mixed origin who achieved their status in a number of ways, and that their "commercial and economic role must have become very important".
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