Ethnos and Koinon 279In the Hellenistic period, the Achaeans’ rejection of the idea thatethnosandkoinon
should be coterminous became widespread. Although the Aetoliankoinonappears to have
been originally limited to ethnic Aetolians, and possibly organized by sub-groups within
theethnos(Thucydides 3.94.4–5; Arrian,Aanabasis1.10.2), it was quickly expanded
to include outsiders before the end of the fourth century. The Aetolians seized Acar-
nanian Oeniadae sometime before 323 and somehow incorporated the communities of
Phocis into their polity before 301. If, then, a sense of ethnic identity had undergirded
the federal experiment in early Classical Phocis, it imposed no strict limit on regional
politics in the Hellenistic period. Much of Thessaly followed after 280 (Scholten 2000:
29–58). Even the Boeotians, who had played the ethnic card heavily in the sixth and fifth
centuries, now incorporated outsiders in theirkoinon, including at least briefly Megara
(Polybius 20.6.7), Locrian Opus (Petrakos 1997: no. 21 line 2; Etienne and Knoepfler
1976: 331–7; Scholten 2000: 259–60), and Euboean Chalcis (IGVII.2724b line 6 with
Knoepfler 1998: 202–3, 207).
In each of these cases, the ethnic outsiders who became members of akoinonreceived
rights and obligations equal to those of the original members who were ethnic insid-
ers. This is most clearly documented for Hellenistic Achaea, where new members were
promised internal autonomy and freedom from garrisons (Peek 1969: no. 25), and where
Achaean officials and citizens of the new memberpolistogether swore oaths to uphold
agreements reached about the terms of incorporation (Thür and Taeuber 1994: no. 16).
Assembly meetings were initially held in the sanctuary of Zeus at Aigion, central to Achaea
proper but quite peripheral as thekoinongrew to incorporate most of the Peloponnese.
Under pressure from new memberpoleiscomplaining about their geographical disad-
vantage, the Achaeans agreed to hold assemblies in various member cities on a rotating
basis (Liv. 38.30.3). Boards of federal magistrates were comprised of ethnic outsiders and
insiders alike—Argives, Arcadians, and Achaeans (IGIV.1^2 .73). Equal representation for
ethnic outsiders in the Boeotiankoinonis likewise attested (IGVII.2724b). The Aeto-
lians may have come to such equity and openness only gradually, but they did soon grant
non-Aetolians the same rights and privileges as Aetolian citizens, including holding high
office (Scholten 2000: 44–5, 63–6, 90–1).
All of this suggests that if ethnicity provided an argument for participation in a regional
politics of cooperation when such arrangements were still entirely novel, that argument
became less relevant as other considerations became evident. Economic considerations
were highly significant.Koinathemselves might desire to expand beyond the bound-
aries of the originalethnosin order to acquire valuable resources. This was certainly a
motivation for the Aetolian seizure of Acarnanian Oeniadae in the late fourth century
(Diodorus Siculus 18.8.2–7; Plutarch,Alexander49.14), a time when they had lost
and were desperately trying to regain access to the Corinthian Gulf. And new potential
members might enjoy significant economic advantages, as I have argued in greater detail
elsewhere (Mackil 2013: 237–325).
Xenophon, deeply anxious about the threats posed by thekoinonto traditionalpolis
autonomy (Bearzot 2004: 45–56), imputes to an ambassador from the northern Greek
city of Acanthus a speech about the sources of the rising power of thekoinonof the Chal-
cideis under the leadership of Olynthus in 382. He cites a territory with rich and varied
resources: plentiful shipbuilding timber; many harbors and ports, each generating signifi-
cant revenues; an abundance of food sustaining a large population (Xenophon,Hellenica