Helots were Peloponnesian Greeks who were enslaved under the Spartan rule.
First helots were Laconians Sparta defeated and conquered. It is possible that the name Helot comes from Helos, the main city in Laconia.
Sparta conquered Messenia around 640 BC – 620 BC. They became agricultural and domestic slaves and sometimes served as military servants as well. Messenians became state-owned slaves who lived in their master’s household. Unlike regular slaves, their master could not declare them free. Spartans usually allowed agricultural helots to keep the excess produce.
Messenians outnumbered the Spartans maybe 20 to one and became a backbone of agricultural production. Spartans kept themselves in continuing military preparedness in order to crush any attempt of rebellion. They also hesitated to join military campaigns far from Sparta for the same reasons. Military force known as Krypteria kept them under control. According to Aristotle, Spartans annually redeclared war against them to justify the use of force.
In wartime helots served as light infantry and as rowers in ships. During the Peloponnesian War they fought as heavy infantry and helots who excelled in battle could earn their freedom. Some 2000 were freed and reputedly later assassinated.