Simple Example:
* The ambitious general plotted the usurpation of the throne, hoping to seize power for himself.
With Emphasis on the Act:
* The usurpation of the ancient king's power by the tyrannical warlord sparked a bloody rebellion.
Focusing on the Consequence:
* The usurpation of the city's water supply left its inhabitants desperate for survival.
In a Figurative Sense:
* The new technology's arrival marked a usurpation of the old methods, rendering them obsolete.
Remember that "usurpation" implies an illegal or forceful seizure of power or rights. It's a strong word with a negative connotation.