Hegemony
Supremacy
noun, の adjective
Those with the rights to leadership have complete hegemony over the country. And they will reign until the end of time.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
あの男が党内の覇権を握っているのです。
That man reigns supreme over the party.