 When they decided to advance again in 279 BC, they split their forces into three divisions.One division was led by Cerethrius against the Thracians and Triballi; another by Bolgios against the Macedonians and Illyrians; and the third against Paionia by Brennus and Acichorius.Bolgios' expedition inflicted heavy losses on the Macedonians and killed their king, Ptolemy Keraunos, but was repulsed by the Macedonian nobleman Sosthenes.