Hwangjeui Aireul Sumgineun Bangbeop

Astelle, the empire's one-day empress brought with her a secret when she left the palace after the divorce: she was pregnant with Emperor Kaizen's child. Six years later, Astelle is living a peaceful life in the countryside with their son until the imperial guards come knocking. Kaizen requires Astelle's consent to receive the key territory of Meilen. With the empire still in turmoil from a rebellion, will Astelle be able to hide her son's identity from these threatening forces, and more importantly, from his father, the emperor?
(Source: Tapas)