, the son of Leonidas, succeeded in effecting the
reforms which had been contemplated by Agis, as well as several others
which regarded military discipline. The effect of these new measures
soon became visible in the increased success of the Spartan arms.
Aratus was so hard pressed that he was compelled to solicit the
assistance of the Macedonians. Both Antigonus Gonatas and his son
Demetrius II.--who had reigned in Macedonia from 239 to 229 B.C. were
now dead, and the government was administered by Antigonus Doson, as
guardian of Philip, the youthful son of Demetrius II. Antigonus Doson
was the grandson of Demetrius Poliorcetes, and the nephew of Antigonus
Gonatas. The Macedonians compelled him to accept the crown; but he
remained faithful to his trust as guardian of Philip, whose mother he
married; and though he had children of his own by her, yet Philip
succeeded him on his death. It was to Antigonus Doson that Aratus
applied for assistance; and though Cleomenes maintained his ground for
some time, he was finally defeated by Antigonus Doson in the fatal
battle of Sellasia in Laconia (B.C. 221). The army of Cleomenes was
almost totally annihilated; he himself was obliged to fly to Egypt; and
Sparta, which for many centuries bad remained unconquered, fell into
the hands of the victor.

The succession of Macedonian kings from Alexander the Great to the
extinction of the monarchy will be seen from the following table:--

B.C.
Philip III. Arrhidaeus . . . . . . . . 323-316
Cassander . . . . . . . . 316-296
Philip IV. . . . . . . . . 296-295
Demetrius I. Poliorcetes . . . . . . . . 294-287
Pyrrhus . . . . . . . . 287-286
Lysimachus . . . . . . . . 286-280
Ptolemy Ceraunus and others . . . . . . . . 280-277
Antigonus Gonatas . . . . . . . . 277-239
Demetrius II . . . . . . . . 239-229
Antigonus Doson . . . . . . . . 229-220
Philip V . . . . . . . . 220-178
Perseus . . . . . . . . 178-167

In the following year Antigonus was succeeded by Philip V., the son of
Demetrius II., who was then about sixteen or seventeen years of age.
His youth encouraged the AEtolians to make predatory