The Electors of Brunswick-Lüneburg or Hannover, the kings of Great Britain, were staunch supporters of the Habsburgs.

Hannover was a new creation as an Eletor. Following the Golden Bull, there used to be only 7 electors. The first change came during the War of the Schmalkaldic League, when the Saxon vote was transferred from one branch of the Saxon dynasty to another. The next change came during the Thirty Years War, when the Palatine vote was granted to Bavaria. These were changes were stretching the 'constitution' but they didn't represent a clean break. When the Palatine was granted a new vote in the peace of Westphalia, it suddenly made the creation of entirely new votes possible. Larger principalities, like Hannover, Württemberg and Hesse-Kassel started living for their own Electoral votes.

In 1692, duringng the Nine Years War with France, the Emperor decided to reward Hannover with their coveted Electoral vote. This was a way to ensure their loyalty in the Protestant north of the Empire, where imperial rule was traditionally weaker than in the south. It also served as a counterweight to Brandenburg, which became ever more powerful following the Thirty Years War. The other Electors didn't accept Hannovers new title immediately. It took untill 1708, during a new war with France over the Spanish succession, that Hannover was recognised as a new Electorate. To keep the balance between Protestant and Catholic Electors, it was also agreed to restore the Emperor's own Bohemian vote.

During the first half of the 18th century, Britain and Austria were allies in most major European wars, as both were enemies of France. Hannover thus supported the Habsburgs in imperial Elections. In any case, the Elections were consensus based affairs, even during the Thirty Years War, Frederick V (actually his representative) had to vote for Ferdinand as Emperor, even as he had usurped his Bohemian Crown.

The only break in the Habsburg line of emperor's came in 1742, during the War of the Australian Succession. Votes were split: Cologne, Bavaria and the Palatinate favoured Charles of Bavaria. Francis, the husband of Maria Theresa was supported by Hannover, Trier and Mainz. Saxony and Prussia initially bremained neutral but were swayed to vote for Bavaria. When Maria Theresa herself was excluded due to disputes over her right to the Bohemian thrones, the vote went to Bavaria. Hannover, Mainz and Trier abstained, as not to disrupt the consensus model of the voting process.

Later Elections went back to a clear Habsburg majority without any disagreements over the Elections. Even as Britain became a ally of Prussia after the diplomatic revolution, when Austria allied France, this did not influence the Elections. Prussia never came close to convince a majority of Electors to its anti-austrian cause, so there was never an opportunity for Britain to side with a non Habsburg Emperor.