Board Thread:General Discussion/@comment-3271485-20150320233013/@comment-26202330-20150321112631

"Rose's Scabbard" pretty much confirms that the final battle (possibly the only battle as well i.e there was just one huge battle to decide the outcome) of the rebellion took place "over five thousand years ago" at the Strawberry Battlefield.

All-in-all, based on what we do know, it just seems far more likely that Greg was told about the events by the Crystal Gems.