The unfortunate physician, while uttering these words, lifted his hands with a look of horror, as if he had beheld some frightful shape, which he could not recognise, usurping the place of his own image in a glass.
There are no more uses of "usurp" in the book.
Show samples from other sources
Henry IV usurped the throne from Richard II while the latter was fighting in Ireland.
I believe there are more instances of the abridgement of the freedom of the people by gradual and silent encroachments of those in power than by violent and sudden usurpations.