usurpation

noun

1. entry to another's property without right or permission

   noun.act

   Synonyms encroachment intrusion trespass violation

   Source: WordNet 3.0

2. wrongfully seizing and holding (an office or powers) by force (especially the seizure of a throne or supreme authority)

   noun.act

   Examples

   A succession of generals who ruled by usurpation.

   Source: WordNet 3.0

3. The act of usurping, or of seizing and enjoying; an authorized, arbitrary assumption and exercise of power, especially an infringing on the rights of others; specifically, the illegal seizure of sovereign power; -- commonly used with <i>of</i>, also used with <i>on</i> or <i>upon</i>; as, the <i>usurpation</i> of a throne; the <i>usurpation</i> of the supreme power.

   noun

   Source: webster1913