Antigonus II gonatas acheives a staedy rule in macedonia and a stable invasion of greece.
This will lead to macedonia getting careless and its loss of Greece, a major impact to its borders, ultimately becoming a roman province in the long-run.
This is an event that has to do with the fall of macedonia. Its borders slowly wittled away time due to alexander the greats death. This leads to more frequent invasion. in an attempt to re-enlarge thier border, they attack rome. the army is deafeated, the plan backfires and macedonia turns into a roman province.
Macedonias army loses against the romans and the macedoinians also lose greece.
This is a major blow to the borders, and plays a substatial role in the romans conqering macedonia.
Rome takes over the macedonian selucids in asia and its last king, Antiochus XII.
This leads to the complete fall of the macedonian empire, affecting the borders over time.