Webster's Revised Unabridged Dictionary · 1913

Usurp

Usurp , transitive verb

[Latin usurpare, usurpatum, to make use of, enjoy, get possession of, usurp; the first part of usurpare is akin to usus use (see Use, n.): compare French usurper.]

To seize, and hold in possession, by force, or without right; as, to usurp a throne; to usurp the prerogatives of the crown; to usurp power; to usurp the right of a patron is to oust or dispossess him.
Alack, thou dost usurp authority. — Shakespeare
Another revolution, to get rid of this illegitimate and usurped government, would of course be perfectly justifiable. — Burke

Usurp is applied to seizure and use of office, functions, powers, rights, etc.; it is not applied to common dispossession of private property.

Usurp , intransitive verb

To commit forcible seizure of place, power, functions, or the like, without right; to commit unjust encroachments; to be, or act as, a usurper.
The parish churches on which the Presbyterians and fanatics had usurped. — Evelyn
And now the Spirits of the Mind Are busy with poor Peter Bell; Upon the rights of visual sense Usurping, with a prevalence More terrible than magic spell. — Wordsworth