Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
From: The History of Rome, by Theodor Mommsen
Translated with the sanction of the author by William Purdie Dickson
Attempt of the Romans to Invade Macedonia
Thus the winter passed away. With the spring of 555 the proconsul Publius Sulpicius broke up from his winter camp, determined to conduct his legions from Apollonia by the shortest route into Macedonia proper. This principal attack from the west was to be supported by three subordinate attacks; on the north by an invasion of the Dardani and Illyrians; on the east by an attack on the part of the combined fleet of the Romans and allies, which assembled at Aegina; while lastly the Athamanes, and the Aetolians also, if the attempt to induce them to share in the struggle should prove successful, were to advance from the south.
After Galba had crossed the mountains pierced by the Apsus (now the Beratind), and had marched through the fertile plain of Dassaretia, he reached the mountain range which separates Illyria from Macedonia, and crossing it, entered the proper Macedonian territory. Philip had marched to meet him; but in the extensive and thinly- peopled regions of Macedonia the antagonists for a time sought each other in vain; at length they met in the province of Lyncestis, a fertile but marshy plain not far from the north-western frontier, and encamped not 1000 paces apart.
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Reference address : https://www.ellopos.net/elpenor/rome/3-08-second-macedonian-war.asp?pg=43