Whose votes elected the Emperor of the Holy Roman Empire?

The emperor of the Holy Roman Empire was elected by a college of prince-electors. A typical group of such electors was one that existed in the 12th century consisting of seven electors including:

• the King of Bohemia
• the Margrave of Brandenburg
• the Count Palatine of the Rhine
• the Duke of Saxony
• the Archbishop of Mainz
• the Archbishop of Trier
• the Archbishop of Cologne