The Still Craft
All the magisters had been friends since childhood, and had studied together. They had an abundance of talent, and took magic beyond what was thought possible at the time.
At a young age, they each found there own way into positions of power, and over the years, increased their influence. By the age of 24, a magister took the throne in the old human empire, and created a new government with the Magisters at its head.
Together, they built up this empire, and began taking control of other, smaller nations. When the youngest reached 35, most of Migna was under their rule.