Nearly 6000 years ago.
The Empire celebrated the birth of Prince Fangyu. The celebrations lasted for weeks, with many people from outside the Continent coming to give their congratulations to the Emperor.
The Dragon Emperor revealed the prince on his first birthday a year later, and he gave him one of the most important treasures that someone from the Imperial Royal family could hold.
The Ebony Sword.
Nobody really knew what it meant to have that sword. To them, it was just a symbol of the Empire, a heirloom to keep. Still, they celebrated the occasion.
The Emperor was happy with his first son, and the Empress was even happier. With the birth of the prince, they were both relieved from the stresses that had plagued them for ages.
Now, the Dragon Emperor wouldn't be suggested to find himself a concubine every time he met someone important.