Riverside Code at Qingming Festival

Set during the Tang Dynasty, this series follows two officials as they unravel a series of mysterious and supernatural events, blending historical intrigue with detective work.
Lu Ling Feng, general of the Jin Wu guards was tasked to investigate these strange cases, but finds himself having to work together with his strongest opponent in Su Wu Ming, the disciple of Di Ren Jie.

Investigating mystery from the past - dealing with manipulations and machinations of rich and powerful - mature love - a closer look at lower- and middle-class life

Well, someone already recommended season 1 but he/she didn't recommended this one.
Both seasons are fantastic

First episode of RCAQF reminded of Louyang. It has many similarities than one could imagine. Just check it out if you really like this drama.