Yo WWHATTTTT no way bro just claimed after this Rome didn’t do large scale assaults across the Rhine? They absolutely did several years in a row and decimated the Germanic tribes. ALSO, Arminius didn’t just used to be a Roman ally, he was one of the head Roman allies in the region and tricked Varus into ‘putting down’ a revolt from another tribe. In reality though when the Roman’s were marching there to help (and Arminius was supposed to be gathering his German troops to help the Roman’s and meet up there) he really just had all his German (they thought Roman allies) set up an ambush.

It wasn’t hidden, it is widely known. Also, did Romans in 9 AD have round shields?