* The Battle of Gettysburg
* The Battle of Midway
However, you don't capitalize "battle" when it's used as a general term:
* The battle for civil rights was long and difficult.
* They fought a battle against poverty.
Here are some helpful guidelines:
* Specific historical events: Capitalize (e.g., The Battle of Hastings)
* General term: Lowercase (e.g., a fierce battle)
* Part of a title: Follow the title's capitalization rules (e.g., "The Battle of the Somme" is capitalized)