The legal system requirement to have an organisation outside of its on legal/morality creation (sovereignty) for the existence if a legal system itself. Which makes States/Kings having arbitrary power (the monopoly of violence)...
...and that suggests the old culture of domestication of foreign kings (placing them in a helm apart from society) and the "killing of kings" (the thugs that create revolutions and their own ruling) as a symble of society's reborn as a popular container to their abuse of power. That is what we today would call the right to popular assembly and arm themselves against tyranny.
A passage from David Greaber in "On Kings".
> The legitimacy of any legal order therefore ultimately rests on illegal acts—usually, acts of illegal violence. Whether one embraces the left solution (that “the people” periodically rise up to exercise their sovereignty through revolutions) or the right solution (that heads of state can exercise sovereignty in their ability to set the legal order aside by declaring exceptions or states of emergency), the paradox itself remains. In practical terms, it translates into a constant political dilemma: How does one distinguish “the people” from a mere unruly mob? How does one know if the hand suspending habeas corpus is that of a contemporary Lincoln or a contemporary Mussolini?
> What I am proposing here is that this paradox has always been with us. Obviously, any thug or bandit who finds he can regularly get away with raping, killing, and plundering at random will not, simply by that fact, come to be seen as a power capable of constituting a moral order or national identity. The overwhelming majority of those who find themselves with the power to do so, and willing to act on it, never think to make such claims—except perhaps among their immediate henchmen. The overwhelming majority of those who do try fail. Yet the potential is always there. Successful thugs do become sovereigns, even creators of new legal and moral systems. And genuine “sovereignty” does always carry with it the potential for arbitrary violence. This is true even in contemporary welfare states: apparently this is the one aspect that, despite liberal hopes, can never be completely reformed away. It is precisely in this that sovereigns resemble gods and that kingship can properly be called “divine.”