The article is devoted to the analysis of information on Hellenistic military settlements, which can be found in the extant letters of Seleucid and Attalid kings. We mean the letter of Antiochus III preserved by Flavius Josephus in his Judean Antiquities, and three letters extant as inscriptions on stone: ‘Ikadion’s inscription’ from the island of Failaka in the Arabian Gulf (Kuwait, middle of the 3rd – early 2nd centuries BC), Antiochus V’s letter from Jamnia-on-the-Sea (Palestine, 163 BC) and Eumenes II’s letter from Kardakon Kome (Lycia, 181 BC). The material of the letters allows to conclude, that there were at least two different types of aforementioned settlements: 1) military settlements in proper sense, inhabited by warriors, whose duty was permanent military service, and members of their families; 2) specific settlements where people generally lived peaceful lives being engaged mostly in agriculture, cults of local sanctuaries etc., but also in some military activities like defense of fortresses. Both types could be protected by the kings in the form of partial or full tax exemption, land grants etc., although the second type got less royal attention of that kind than the first one. The existence of the second type can be explained by the fact that the oldest type of army, quite actual in the ancient world, was militia of a community. Thence the second type of settlements can be nothing else than communities, whose militias were used by the Hellenistic kings in their military activities alongside the professional army.