Well there is a difference between a campaign and a battle. Sometimes I feel like Hannibal, winning multiple "decisive" victories over my opponent only to find another full stack awaiting my now depleted army for all my heroic efforts.

Also, a campaign can involves armies at multiple locations while battles can only take place at one point generally speaking. For example, I can campaign to take Asia Minor from the Seleucids and land armies at Pergamon, Sardis, Sidon, and Tarsus. Geographically they are completely different and do not constitute a single battle, however, they form part of a single campaign. I suppose you could say "The Battle for Asia Minor" but this would be a modern way of describing battles.