In Critias, Plato says that the 10 Atlantean kings held a meeting every other 5 or 6th year alternately. In the meeting they would consult their common interests, inquire if anyone had transgressed and if anyone had dedicate their sentence together. The kings had complete control over their citizens and most over their law (they had to follow the laws Poseidon had inscribed on the pillar).
What kind of government would this be?