Charlemagne briefly reunited much of western europe by

By force. 
He used a well organized and well led army to conquer Western Europe, then introduced administrative reforms to help run it all. The Pope rewarded him for spreading Christianity (and removing the Lombard threat to Rome in Italy) by crowning him Emperor of the West on Christmas Day 800

Should be the answer

A. democrat, republican, whig, other.(the democratic and republican parties are the main 2 american political parties, the whig party was popular among the early presidents, and the “other” option allows for outliers)