His reign is noted for his attempts to transform Sparta into a Hellenistic kingdom and to recover its former pre-eminence in Greece, notably against the kings Antigonos Gonatas of Macedonia and Pyrrhus of Epirus.

The first part of Areus' reign was dominated by the influence of his uncle and regent Cleonymus, a skilled general who campaigned in Greece and abroad at the head of mercenary armies.

Areus' first record in the scanty ancient sources took place in 281 BC, when he led an alliance of Greek city-states to challenge Macedonian control over Greece, but was rapidly defeated by the Aitolian League (allied with Macedonia).

Thanks to the prestige of this victory, Areus founded another alliance in 267 BC with Athens and Egypt against the Macedonian king Antigonos Gonatas.

In order to facilitate his recruitment of Jewish mercenaries, Areus claimed a shared ancestry with the Jews, who answered favourably and later repeatedly renewed their friendship with Sparta, even though the reality of this Spartan-Jewish connection is disputed.

[10] Moreover, succession disputes were normally settled before the ekklesia—the citizen assembly at Sparta—not the Gerousia, as in 400 when Agesilaus II was chosen king against the initial claim of his nephew Leotychidas.

[11] Cleonymus retained a prominent place during the first half of Areus' reign, commanding mercenary armies with official support, such as in 303, when Sparta sent him to help Tarentum against Lucanians and the Roman Republic.

[15] In 281–280, the Wars of the Diadochi—the former generals of Alexander the Great—came to an end with the deaths of Lysimachus, king of Macedonia, and Seleucus, founder of the Seleucid Empire.

In Greece, many cities immediately attempted to recover their independence from the new Macedonian king Antigonos Gonatas, and Sparta is found leading allies for the first time since the defeat of Agis III at Megalopolis in 331.

[16] Sparta did not frontally attack Macedonia though, targeting instead its weaker ally, the Aitolian League, which had taken control of the Panhellenic sanctuary of Delphi a few years before.

[19][20] Areus was chosen by several other states to lead the alliance against the Aitolians, perhaps because the campaigns of Cleonymus made a good impression, and Sparta was seen as producing capable commanders again.

[24] Other possible allies were Megara, Boeotia, Argos, Epidauros, Elis, Athens and Western Crete, but the state of evidence is very thin.

[48] Pyrrhus' first confrontation was instead against Antigonos Gonatas, as he coveted the Macedonian throne, during which he gave Cleonymus the important command of the Epirote phalanx.

[54] Pyrrhus disguised his real intentions to the Spartans, by assuring them that his only ambition was to remove Gonatas' influence from the Peloponnese, and to bring his young sons to Sparta so they could be trained in the Agoge.

[55][56] The Spartans were therefore completely caught off-guard when Pyrrhus attacked them and besieged their city, as Areus was campaigning in Crete, supporting Gortyn in a war against Knossos.

[59] Although its inhabitants had been Spartan helots before the Battle of Leuctra, relationships between the two cities considerably improved during the third century, as evidences show ties between respective aristocrats.

[67] As both Athens and Sparta had been allied with Egypt before concluding an alliance between them, it seems that the initiative came from Ptolemy II, who was an enemy of Gonatas and had tried to get a foothold in mainland Greece.

[68][69][70][71] Dated from 268 to 267, the text of the Athenian decree sealing the alliance with Sparta is still extent, and is the major source of these otherwise poorly documented events.

[75] Elis, Achaia, and five Arcadian cities (Tegea, Mantineia, Orchomenos, Phigalia, and Kaphyae) are cited; Corinth, Argos, and Megalopolis remained on the side of Gonatas, Messenia was neutral.

[78][79] Areus also counted several allies in Crete: Polyrrenia, Phalasarna, Gortyn, Itanos, Olous, Aptera, Rhithymna, and Lyttos, while Knossos might have joined later.

[67][84] Despite the large number of participants, the anti-Macedonian alliance suffered from the isolation of its individual members, while Gonatas' territories formed one block.

[86][87][88] Ptolemy helped Athens by sending his admiral Patroklos, but his forces were not sufficient to dislodge Gonatas from Piraeus, although he built several forts on the shore of Attica.

[97] In about 265, a battle took place near Corinth between the bulk of Gonatas' army and that of Areus, in which the latter was killed, and apparently a lot of his troops as well, because Sparta is not found attacking the isthmus again.

[102][103] While the Spartan kingship had been an anachronism in Classical Greece (5th and 4th centuries BC), monarchy became the prevalent form of government during the Hellenistic era.

[104] The Spartan kings were indeed the last of the Heracleidae—the descendants of Herakles—following the extinction of the Argead dynasty of Macedonia in 309 BC, an important source of prestige within the Greek world.

[122] In the 280s or 270s Areus hired the sculptor Eutychides of Sikyon to create an allegory of the Eurotas river, which was praised by Pliny the Elder and perhaps copied as far as Salamis in Cyprus.

[108] Although he still retained the constitutional framework of Sparta, Areus' enhancement of his kingship dangerously shook the institutional balance in the city, which later lead to the abolition of dyarchy and the reduction the ephorate and Gerousia under Kleomenes III and Nabis.

[133] Flavius Josephus, a Jewish historian of the 1st century AD, also refers to these letters, which all establish and renew friendship ties between Sparta and Judea.

This puzzling connection between a Greek state and a people subject of Ptolemaic Egypt has attracted considerable attention among modern scholars.

[142] Gruen thinks instead that this correspondence is a Jewish invention, which results from the need for them to find their place in the new Hellenistic order that followed the conquest of the Persian Empire by Alexander the Great.