The Middle Continent Ancient Kingdom was an Imperial Lineage that existed during the Desolate Expansion Era. During that era it was an unparalleled giant in the Mortal Emperor World and wasn't any weaker than the War God Temple.
Tian Tu Annihilation Age
Before Tian Tu became an Immortal Emperor, the Middle Continent Ancient Kingdom had the highest chance of defeating his lineage. In the end, they chose to join Tian Tu's banner instead. They assumed that after helping Tian Tu to become an Immortal Emperor, they would become his most meritorious vassals. Little did they know that the day when Tian Tu unified the heaven and earth would be the day of their demise.