The administrative division of Achaemenid Persia is still a matter of debate.
Most scholars agree that the satrapic system was hierarchical. There were main and minor satrapies, with the latter ruled by the former. In the Bisitun inscription, 23 lands are mentioned, which are usually assumed to represent the main satrapies during the reign of Darius. Herodotus’ list of 20 satrapies is an incomplete account of both main and minor satrapies, with a clear bias toward the western regions of the empire, while the eastern regions are very poorly represented.
Khorikyan discusses these questions, and based on his papers, I made a map of the main satrapy of Armenia mentioned in Bisitun and other sub-satrapies mentioned in Herodotus.
Saspeires or Sapirs, according to Herodotus, were located between Colchis and Media. For this reason, they have been placed in modern Armenia. However, if modern Azerbaijan was part of the main Median satrapy (map 3), then a location in eastern Georgia is also possible. Locating the Saspeirs in modern Armenia has no solid arguments. Neither in the Urartian period nor in the later Armenian period is there a single toponym that can be securely linked to Saspeir. Meanwhile, such a toponym exists in Georgia: Iberia. Some scholars have proposed the theory that “sa-” is a Georgian prefix for land, as in Sakartvelo, and that the true root in Saspeires/Sapirs is *speir or *pir, which may be the proto-form of Greek Iberia and Latin Hiberia. However this theory has an important caveat. The Iberia is an exonym, that Georgians never used to describe their country. Another possibility is that the initial sa- is not a prefix but rather part of a root. Edwin Guest proposes a plausible theory how dialectical variation of Greek could have created variants like Saspeir, Sapir and Sabir. Later based on the phonetic developments of Ionian dialect of Greek they evolved to Iberia.
Now in Greek we sometimes find an s intruding itself under circumstances not very dissimilar to the present ; e.g. hespomai for hepornai, speos for peon, smikros for mikros, skapetos for kapetos, &c. If the second sibilant in Saspeires may be thus accounted for, we may consider Saspeires, Sapeires, and its dialectical variety Sabeires, as merely varied forms of the same word.
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The Phocaeans were Ionians, and in the Ionic family of dialects there was a tendency to change the initial s into a breathing, and the diphthong ei into ē, so that Iberes may well have been the Phocaean pronunciation of Sabeires.
From a genetic point of view, we know that Iberian-related ancestry had already formed in eastern Georgia in early antiquity. Therefore, some early polity with Georgian presence must have existed there during the Achaemenid period. The Saspeirs could be the precursor of Iberia.
Matiene is another obscure tribe mentioned alongside the Saspeirs. Matiene existed in several places: in Anatolia and northwestern Iran. Khorikyan cites at least one Greek source in which Matiene is mentioned in a Caucasian context, and based on this, he places it in the headwaters of the Kura River.
From a genetic point of view, the presence of R1a and Q2 in the ancient Samtskhe region is remarkable. It could be related to Persian rule there, but it may also reflect a different influence from the Iranian plateau, with the Matiene being a plausible candidate.
Not much is known about the Alarodi—only two sentences mention them—so their localization will remain speculative.
In sum, Khorikyan proposes that the 18th satrapy was located north of Armenia rather than in eastern Armenia.
Finally, the Pactyuce mentioned alongside the Armenians is most likely a corrupted form of Patuka, a Luwian or Hittite term derived from peda, meaning “land,” from which Katpatuka is derived, meaning “lower land.” A village named Patuk is attested near Kharberd (Elazığ).
The third map shows the main satrapies according to Jacobs, while the second map shows the temporal expansion of the empire according to Mladiov.
Referenc
Edwin Guest, Origines Celticae, vol. II, “Origines Celticae,” Chapter II, p. 2, p. 60-61.