When you consider that the Bengals were founded in Cincinnati mostly so Paul Brown could stick it to the franchise that is named after him, but also forced him out of football for a time, the rivalry between Cincinnati and Cleveland on the gridiron has always had natural animosity.
However, apart from a brief stretch in the 1980s, both teams being good at the same time has been rare. Thus, the rivalry is often overlooked on a national scale.
In fact, the most famous moment in its history took place while Cincinnati wasn’t even playing the Browns.