Pausanias Description of Greece 1.16.2

[2] After these successes, which were shortly followed by the fall of Lysimachus, he entrusted to his son Antiochus all his empire in Asia , and himself proceeded rapidly towards Macedonia , having with him an army both of Greeks and of foreigners. But Ptolemy, brother of Lysandra, had taken refuge with him from Lysimachus; this man, an adventurous character named for this reason the Thunderbolt, when the army of Seleucus had advanced as far as Lysimachea, assassinated Seleucus, allowed the kings to seize his wealth ¹ , and ruled over Macedonia until, being the first of the kings to my knowledge to dare to meet the Gauls in battle, he was killed by the foreigners. ² The empire was recovered by Antigonus, son of Demetrius.

[2] After these successes, which were shortly followed by the fall of Lysimakhos, he [= Seleukos] entrusted to his son Antiokhos all his empire [ arkhē] in Asia (Minor), and himself proceeded rapidly towards Macedonia, having with him an army both of Greeks [Hellēnes] and of barbarians. But Ptolemy, brother of Lysandra, had taken refuge with him from Lysimakhos; this man [= Ptolemy], who was in any case prone to be-daring [ tolmân] and for this reason was called Thunderbolt [ Keraunos], [accomplished quite a daring act] when the army of Seleukos had advanced as far as Lysimakheia: he [= Ptolemy] killed Seleukos by stealth. Then he turned over to the [other] kings [ basileîs] his possessions [= the possessions of Seleukos], 62

while he [= Ptolemy] ruled-as-king [ basileuein] over Macedonia until, being as far as we know the first of the kings [ basileîs] to dare [ tolmân] to face the Gauls [Galatai] in battle, he was killed by thesebarbarians. 63

The empire [ arkhē] was restored-to-safety [ sōzesthai] by Antigonos son of Demetrios.