At age nine, Alexei became King in title only. The Council actually took over the rulings. Alexei was able to bend those rules and create several laws before he handed the power to the Council. At age twelve, a monster is considered an adult (though not always sexually), so Alexei was able to take control then. He did have much more influence over the Council than his father, who went through the same process before when his father died as well before he came of age. Alexei had a way of manipulating the Council to do what he wanted (and still does) while Gideon just sat back and let them do everything for him. It was during the years when Alexei was named King by title only that the Council established the laws that humans should be enslaved.