I'm not saying some of the shows aren't enjoyable to watch, but they aren't about history.
Usually it's things like "secret" government facilities, lights in the sky, cattle mutilation etc; they did recently come up with a show called Ancient Aliens or somthing along those lines, that one does get a bit more historyish, but that isn't their only aliens show.
Ah, the Ancient Aliens series is the only one I'm aware of. Their documentaries on the early presidents are great, but lengthy.
According to my count of http://www.history.com/shows
(haven't doublechecked the numbers), they got the following:
Aliens (counting ancient aliens): 2
End of the World: 7
Miscelaneous fiction: 5
Modern things: 10
Non-history related reality shows: 16
Actual History: 38
They indeed have a significant amount of actual history shows, but my subjective experience is those occupy only a surprisingly small fraction of the weekly grid.
ps:many shows there i don't recognize and there are a couple i've seen on TV that i didn't spot there, perhaps they use some programs from other companies over here, and i think some of the ones listed on that page aren't being aired regularly anymore.