It seems Ruby Lin and Yuan Hong are specialised in Ancient drama, no? It has being a while since we had a good Palace drama (and Empress of China doesn’t count for me because they totally messed up the life story of Wu Zetian). This drama is called Singing All Along or Elegant Empire or Song of Long Journey (I guess the title is subject to change until the official broadcast). Excluding Ruby Lin, the cast has a bunch of pretty boys: Yuan Hong, Kenny Kwan, Mao Zi Jun, and Li Jia Hang. The story is based on a novel called Xiu Li Jiang Shan 秀麗江山.
Here is the synopsys from spcnet: source
At the start of the New Dynasty, LiuXiu studied at ChangAn where he met DengYu 邓禹, LiuYuan刘玄, FengYi冯异, young but brilliant scholars of their time. Here he also met the Young YinLiHua阴丽华. Some Years later, civil war broke the country was in chaos. LiuXiu participated in his brother LiuYan劉演’s rebellion, whilst YinLiHua cross-dressed to join in the war as the male YinJi. Through many great battles, LiuXiu fought amongst those who would become his lifelong allies and comrades, only to have their efforts stolen when LiuYuan刘玄 was crowned Emperor. Challenged by the two Brother’s glory, LiuYuan had LiuYan assasinated. In order to avoid his fate LiuXiu married YinLiHua as she came from a powerful noble family, and receeded into endulgence to have the Emperor lower his guard against him and sent him to the North where LiuXiu was able to regroup. Though life in the North was harsh, one by one, his friends and allies came to join his campaign. When a Worlord of HeBei suggested an marital alliance to his daughter, LiuXiu painfully parted with his beloved wife. Step by Step LiuXiu claimed the throne and founded Easten Han and after decades of efforts finally restored peace across the land.