I was looking through the drama timeline by Lorell above and it seems the majority of historical cdramas (excluding Republic/Pre-Modern) take place in Qing China. which was actually a foreign Manchu dynasty. The Manchu leaders did a lot to suppress the original Han culture and promote the Manchu culture, like forcing the queue hairstyle and Manchu dress. I thought China took the most pride in their Han culture, so it is a bit surprising to me that there are so many dramas that are set with this time period/culture. After all, there are hardly any dramas set during the other foreign dynasty (Yuan/Mongol). Any particular reason why? 

P.S I hope doesn't come off as judgmental/ethnocentric in any way!

Idk, I'm new to Chinese dramas and I see more non-Qing dynasty historical dramas, thus no queue hairstyle. 

Only one I've seen so far, apart from certain movies, is Scarlet heart. Again I'm still very new to Chinese Dramas. I've seen Imperial Doctress, Wei Young and currently watching Princess Agents but I think these are more tied to fantasy than history.
I asked my dad the same thing a while ago. His reply was that 1. there's probably more info on the Qing dynasty as it's the latest dynasty before the Republic and 2. this period also has a lot of (known) events happening for them to base the dramas off of. (I.e. There's a story to tell if there's war, but a story about a peaceful dynasty is kind of boring). 
@Antonin: I tend to veer more towards non-Qing dramas (I'm. um, quite shallow that way...)

@CheriLynzzz: Thanks! That makes sense. I guess I thought that the entertainment industry would want to promote "real" Chinese culture, not to mention taking advantage of more aesthetically-pleasing eras.  
Wow, this is interesting information. I used to hate the Qing dynasty dramas because of their hair (LOL). But I watched ALL the ancient dramas on DramaFever and wasn't ready to cancel, so I started watching a few and some of them are pretty good. It's interesting to see their take on Kangxi emperor and his sons, and how they make it dramatic and spin in fiction with history. 

A few of my favorites are:
Scarlet Heart (Cecilia Liu, Nicky Wu)
Life and Times of a Sentinel (Steven Ma, Kenneth Ma, Power Chan)
Gilded Chopsticks (this one was HILARIOUS, it's a comedy w/ Wong Cho-Lam, Ben Wong, Nancy Wu)