Britain vs Londinium

Britain

name

  • The United Kingdom. 

  • Brittany. 

  • The British Isles. 

  • The island of Great Britain, consisting of England, Scotland and Wales, especially during antiquity. 

  • The British state and its dominions and holdings; the British Empire. 

  • The British Empire. 

Londinium

name

  • Synonym of Modern London A city in England, United Kingdom 

  • A city in Britannia, Roman Empire An ancient settlement in the area of modern London. 

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