Regus had been through a lot in his life.
While the Aurelius clan was wealthy during his rise to power, it wasn't the most affluent clan amongst all others.
He had earned his way to becoming the general of the then royal army through sheer strength and had promoted himself and his clan to take the number one spot in the rankings by revolutionising it's military and talent upbringing structure.
He had married only after he became king and even after he was married he took a decade more to conceive children with his wife.
The reason behind why he took so long to have a child was because he wanted to solidify his position as the monarch and make sure that if he brought a new soul into this world, he could do it justice and make it a greater king than he was.
Unfortunately for him, his first son Marcus was an utter disappointment.