usurp
/juːˈzəːp,jʊˈzəːp/
verb
take (a position of power or importance) illegally or by force.
"Richard usurped the throne"
Similar:
seize
take over
expropriate
take possession of
take
appropriate
steal
wrest
arrogate
commandeer
annex
assume
take the place of (someone in a position of power)...