The Electors (German: Kurfürsten) had the function of electing the king of Germany preparatory to his accession as the next emperor of the Holy Roman Empire, though until the 12th century they often simply formalized what was in fact a dynastic succession.
Varying in number only between six and ten from the 13th century to the Empire's end in 1806, the electors were drawn from the senior rulers of lands within the Empire. In a document known as the Golden Bull (1356) their status was regulated by the emperor Charles IV, who recognised them as quasi-independent rulers within their own domains.
The Bull stipulated that the dignity of elector should be held by the archbishops of Trier, Mainz and Cologne, the king of Bohemia, the duke of Saxony, the margrave of Brandenburg and the count palatine of the Rhine (whose lands were known as the Palatinate. These rulers remained the Empire's electors until 1623. Later, the dukes of Bavaria and Brunswick-Lüneburg (Hanover) were added, and in 1803 (shortly before the Empire was abolished by Napoleon I) also Baden, Wuerttemberg and Hesse.