Sparta's conquest of neighbouring Laconia and then of Messenia reduced their populations to the status of helots: unfree cultivators tied to allotments, obliged to hand over a fixed share of their produce to Spartan citizen landholders, and owned by the state rather than by private masters. Unlike chattel slaves elsewhere in Greece, helots lived in their own families and communities and retained a collective identity, which is why Messenian helots could be constituted as a free polity when Thebes liberated Messenia in 369 BCE and founded the city of Messene. Ancient sources report that the Spartan ephors declared war on the helots every year so that killing one carried no religious pollution, and that a body of young Spartans, the krypteia, was sent into the countryside to intimidate and kill helots judged dangerous; Thucydides records the disappearance of some 2,000 helots who had been invited to claim their freedom. The system is included here as a case of a population held in place by state coercion over centuries rather than moved, and almost everything known about it comes from non-Spartan Greek authors.
The Spartan state held the conquered populations of Laconia and Messenia as helots — unfree agricultural labourers bound to the land and owned collectively by the community rather than by individuals
No count survives. Estimates are reconstructed from the size of the Spartiate citizen body, land-allotment arithmetic and Herodotus' claim of seven helots per Spartiate at Plataea; Figueira's modelling gives roughly 170,000-224,000 helots, while more cautious readings put the figure nearer 140,000. Messenians were the larger part.
No range can be given for the deaths caused over three centuries. The single best-attested incident is Thucydides' report that about 2,000 helots who had been promised freedom were made to disappear; systematic mortality from the krypteia and from suppression of helot revolts is undocumented.
Compulsory agricultural labour, confinement to allotted land, and the killing of helots by the krypteia and the disappearance of 2,000 helots are reported by Thucydides, Plutarch and other Greek authors as summarised by Livius.org and Britannica.
Greece