source: In response to the assertion of "George RR Martin writing the Lion King" : gifs

verb with object

take (a position of power or importance) illegally or by force:

｟かたく｠ 〈権力･地位など〉を不法に奪う, 強奪する; 〈土地など〉を不法に占有する

e.g. Richard usurped the throne.

take the place of (someone in a position of power) illegally; supplant:

e.g. the Hanoverian dynasty had usurped the Stuarts.

no object (usurp on/upon) archaic encroach or infringe upon (someone's rights):

e.g. the Church had usurped upon the domain of the state.

usurpation |ˌyo͞osərˈpāSH(ə)n, yo͞ozərˈpāSH(ə)n| noun

Middle English (in the sense ‘appropriate a right wrongfully’): from Old French usurper, from Latin usurpare ‘seize for use’.