References:

http://www.encyclopedia.com/topic/Charlemagne.aspx

http://www.bbc.co.uk/history/historic_figures/charlemagne.shtml

http://www.notablebiographies.com/Ch-Co/Charlemagne.html

(http://dictionary.cambridge.org/us/dictionary/english/power, http://www.dictionary.com/browse/power, 

http://www.merriam-webster.com/dictionary/power)

(http://www.dictionary.com/browse/authority,

  https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=definition%20of%20authority,

  http://dictionary.cambridge.org/dictionary/english/authority)

www.merriam-webster.com/dictionary/state

http://www.dictionary.com/browse/state

http://www.oxforddictionaries.com/us/definition/american_english/state