Only recently started getting back into gridiron now I can get it on TV.
Didn't realise that the Baltimore Ravens are really the pre '96 Cleveland Browns.
Must have been a bummer for Browns fans when post '96 'their team' albeit the Ravens won 2 Super Bowls.
Quite a lot of things like that in the NFL.
The Houston Texans are in the same division as the Tennessee Titans (formerly the Houston Oilers). Baltimore lost their own team when the Colts moved to Indianapolis virtually overnight.
The Cardinals have played in Chicago, St. Louis and Arizona. Rams have played in Cleveland, Los Angeles, St. Louis and back to Los Angeles. Raiders have moved from Oakland to Los Angeles and back again (and might move to Las Vegas soon). The Chargers appear near-certain to move to Los Angeles.
Oh and I think the Kansas City Chiefs were briefly the Dallas Texans.