Diodorus (xv, 54) states both the arrival of Jason in Bœotia, and the out-march of Archidamus from Sparta, to have taken place, not after the battle of Leuktra, but before it. Jason (he says) came with a considerable force to the aid of the Thebans. He prevailed upon Kleombrotus, who doubted the sufficiency of his own numbers, to agree to a truce and to evacuate Bœotia. But as Kleombrotus was marching homeward, he met Archidamus with a second Lacedæmonian army, on his way to Bœotia, by order of the ephors, for the purpose of reinforcing him. Accordingly Kleombrotus, finding himself thus unexpectedly strengthened, openly broke the truce just concluded, and marched back with Archidamus to Leuktra. Here they fought the battle, Kleombrotus commanding the right wing, and Archidamus the left. They sustained a complete defeat, in which Kleombrotus was slain; the result being the same on both statements.
We must here make our election between the narrative of Xenophon and that of Diodorus. That the authority of the former is greater, speaking generally, I need hardly remark; nevertheless his philo-Laconian partialities become so glaring and preponderant, during these latter books of the Hellenica (where he is discharging the mournful duty of recounting the humiliation of Sparta), as to afford some color for the suspicions of Palmerius, Morus, and Schneider, who think that Xenophon has concealed the direct violation of truce on the part of the Spartans, and that the facts really occurred as Diodorus has described them. See Schneider ad Xen. Hellen. vi, 4, 5, 6.
It will be found, however, on examining the facts, that such suspicion ought not to be admitted, and that there are grounds for preferring the narrative of Xenophon.
1. He explains to us how it happened that the remains of the Spartan army, after the defeat of Leuktra, escaped out of Bœotia. Jason arrives after the battle, and prevails upon the Thebans to allow them to retreat under a truce; Archidamus also arrives after the battle to take them up. If the defeat had taken place under the circumstances mentioned by Diodorus,—Archidamus and the survivors would have found it scarcely possible to escape out of Bœotia.
2. If Diodorus relates correctly, there must have been a violation of truce on the part of Kleombrotus and the Lacedæmonians, as glaring as any that occurs in Grecian history. But such violation is never afterwards alluded to by any one, among the misdeeds of the Lacedæmonians.
3. A part, and an essential part, of the story of Diodorus, is, that Archidamus was present and fought at Leuktra. But we have independent evidence rendering it almost certain that he was not there. Whoever reads the Discourse of Isokrates called Archidamus (Or. vi, sect. 9, 10, 129), will see that such observations could not have been put into the mouth of Archidamus, if he had been present there, and (of course) in joint command with Kleombrotus.
4. If Diodorus be correct, Sparta must have levied a new army from her allies, just after having sworn the peace, which peace exonerated her allies from everything like obligation to follow her headship; and a new army, not for the purpose of extricating defeated comrades in Bœotia, but for pure aggression against Thebes. This, to say the least, is eminently improbable.
On these grounds, I adhere to Xenophon and depart from Diodorus.
[403] Xenoph. Rep. Lac. c. ix; Plutarch, Agesil. c. 30.
[404] Thucyd. v, 34.