I was watching one of those Lego DC movies with my nephew and noticed that Batman having a HARD hate-on for Superman (making "alien" comments every 5 minutes under his breath). Granted it was played for laughs as it was REALLY one sided with Supes not even paying attention to Bats, but as a fan of the characters, it rubbed me the wrong way.
Looking back after that I've noticed that most, if not all recent adaptions with both Batman and Superman in them have had some sort of rivalry, whether it be Injustice, the DCEU, DCAU, etc. It has gotten to the the point where Batman could give Lex Luthor pointers about Superman. It has even spilled over into the fan bases of the respective characters. I'm wondering when it started? Was it Frank Miller? Did it happen before TDKR? I know that in most Marvel properties the superheroes often fought each other in their first meetings, but I think with DC it was more "chummy". I suppose the heroes being more friendly toward each other was due to the differing time periods/ages that the most popular characters met.
When did this rivalry start? Both between the characters and fans?