annex vs usurp

annex

verb
  • To add something to another thing, especially territory; to incorporate. 

  • To attach or connect, as a consequence, condition, etc. 

  • To join; to be united. 

noun
  • An appendix to a book or document. 

  • An addition to the territory of a country or state, from a neighbouring country or state, normally by military force. 

  • An addition, an extension. 

  • An addition or extension to a building. 

usurp

verb
  • To take the place rightfully belonging to someone or something else. 

  • To seize power from another, usually by illegitimate means. 

  • To use and assume the coat of arms of another person. 

How often have the words annex and usurp occurred in a corpus of books? (source: Google Ngram Viewer )