[Frumious Bandersnatch]

You've already indicated that you don't believe that "supreme" and "sovereign" are synonomous.  Therefore it is bootless to continue.  BTW, "The Sovereign" as you use it would be translated into "The Supreme one."  IOW, there is nothing higher.

[lentulusgracchus]

Concerning definitions, since you doubt me, here are a couple I dredged up using the dictionary on Findlaw:

sovereign
Variants: also sovran

1: possessed of supreme power
Example: a {h,2}sovereign ruler

2: enjoying autonomy
Example: {h,2}sovereign states

3: relating to, characteristic of, or befitting a sovereign

sovereignty
Variants:also sovranty ['sä-vren-te, 'se-, -ve-ren-]

pl: -ties

1 a: supreme power esp. over a body politic

b: freedom from external control: "autonomy"

2: one that is sovereign

esp
: an autonomous state

dual sovereignty doctrine
: a doctrine holding that more than one sovereign (as a state government and the federal government) may prosecute an individual without violating the prohibition against double jeopardy if the individual's act breaks the laws of each sovereignty

Just so you can't hold forth that I'm pulling all these words out of my......wig.