usurp
verb.
seize and take control without authority and possibly with force; take as one's right or possession
He assumed to himself the right to fill all positions in the town|he usurped my rights|She seized control of the throne after her husband died
Synonym: arrogate, assume, seize, take over
verb.
take the place of
gloom had usurped mirth at the party after the news of the terrorist act broke