300-1850 saw hundreds of battles with elephants.
Who actually knows how many battles included war elephants. Maybe you mean all elephants like circus elephants. My rule sets allow elephants in field battles. I generally think of those as war elephants.
This topic is Renaissance (a period in European history) War Game Rules. This period begins in the 14th century and ends in the 17th century. I do not think any European nation included war elephants in their forces during the Renaissance, but no matter what happened you can include them in battles using my rules.
Maybe I should offer a rule set entitled Indian War Game Rules or Elephant War Game Rules.