The origins of the helots are disputed. One theory is that when the Spartans realized they needed more arable land they looked to the southwest to the more fertile soil of Messenia. The helots were conquered Laconians whom the Spartans made subservient.
One version that is not well-received by modern historians, but was accepted in antiquity, is that of Ephorus, a 4th century B.C. Greek historian. Ephorus says helots are named for the city they came from, Helos (in the Peloponnese), which Kennell [see citation below] says is not linguistically plausible. After the Achaeans left the Peloponnese and headed for Ionia, the Spartans gained control, but they needed bodies. Area communities were ordered to be tributaries. Most communities agreed, but Helos refused. Sparta attacked the city and forced its inhabitants, known as Helots, into slavery.
Helots could become freedmen, neodamodes, as a reward for their military service. They might also be mothones (or mothakes) who were reared with Spartiates as their companions and attendants. They might also be nothoi 'bastards', neither citizen nor helot, but illegitimate children of Spartan fathers and helot mothers.
Helots were probably treated like public slaves. Many worked the land to support the Spartiate, although helots could keep what they grew that the Spartans didn't require and might live in their own communities. Others were attendants. They could be killed or whipped, but probably couldn't be sold outside Laconia.
Myron of Priene, author of a history of the First Messenian War, describes Helot clothing as a soft leather cap and animal skin coat.
Spartans A New History
Nigel M. Kennell
The 7th century B.C. Spartan poet Tyrtaeus wrote "just like donkeys, worn down by heavy burdens" [Kennell p. 80], which is thought to describe the helots.