Sentence:  The theory of sovereignty was an invaluable weapon in the hands of the monarch in his contest with the other claimants to authority; it gave a theoretical foundation for the emerging national <WSD>absolute state</WSD>, and it clearly forecast the line that political evolution was to follow. 
Meaning of the word marked with <WSD> tags:  A state with absolute sovereignty and authority, in contrast with e.g. a feudal state.