Illustration from 1341 of electors in deliberation (left to right: Archbishop of Cologne, Archbishop of Mainz, Archbishop of Trier, Count Palatine of the Rhine, Duke of Saxony, Margrave of Brandenburg and King of Bohemia).
Choosing the king. At the top: the three ecclesiastical princes choosing the king, pointing at him. At the centre: the Count Palatine of the Rhine hands over a golden bowl, acting as a servant. Behind him, the Duke of Saxony with his marshall's staff and the Margrave of Brandenburg bringing a bowl of warm water, as a valet. Below, the new king in front of the great men of the empire (HeidelbergSachsenspiegel, around 1300)
From the 13th century onwards, the Prince-Electors had the privilege of electing the King of the Romans, who would be crowned by the Pope as Holy Roman Emperor. Charles V was the last to be a crowned Emperor (elected 1519, crowned 1530); his successors were elected Emperors directly by the electoral college, each being titled "Elected Emperor of the Romans" (German: erwählter Römischer Kaiser; Latin: electus Romanorum imperator). In practice, every emperor from 1440 onwards (except for Charles VII and Francis I) came from the Austrian House of Habsburg, and the Electors merely ratified the Habsburg succession.
The dignity of Elector carried great prestige and was considered to be second only to that of King or Emperor. The Electors had exclusive privileges that were not shared with the other princes of the Empire, and they continued to hold their original titles alongside that of Elector. The heir apparent to a secular prince-elector was known as an electoral prince (German: Kurprinz).
The German element Kur- is based on the Middle High German irregular verb kiesen and is related etymologically to the English word choose (cf. Old Englishceosan[tʃeo̯zan], participle coren 'having been chosen' and Gothickiusan). In English, the "s"/"r" mix in the Germanic verb conjugation has been regularized to "s" throughout, while German retains the r in Kur-. There is also a modern German verb küren which means 'to choose' in a ceremonial sense. Fürst is German for 'prince', but while the German language distinguishes between the head of a principality (der Fürst) and the son of a monarch (der Prinz), English uses prince for both concepts. Fürst itself is related to English first and is thus the 'foremost' person in his realm. Note that 'prince' derives from Latin princeps, which carried the same meaning.