Most of the historical territory of Hanover forms the greater part of the German state of Lower Saxony but excludes certain areas.
From 1714 to 1837, it was joined in a personal union with the United Kingdom, which terminated upon the accession in Britain of Queen Victoria, as in Hanover, a woman could not rule if there was a male descendant.
The territories were named after notable towns where the dukes had (or had had at one time) their residences, e.g. Calenberg, Göttingen, Grubenhagen, Lüneburg, Wolfenbüttel.
The line that would lead to the House of Hanover was that of Bernard, one of the three sons of Duke Magnus II who had jointly ruled a united Duchy of Brunswick since 1388, but who partitioned the territory in 1428 and 1432.
Henry III's son Augustus became Duke of Brunswick-Wolfenbüttel and his descendants eventually ruled the Duchy of Brunswick.
In 1692, the Holy Roman Emperor, Leopold I, elevated George's son, Duke Ernest Augustus to the rank of Elector of the Empire as a reward for aid given in the War of the Grand Alliance.
There were protests against the addition of a new Elector, and the elevation did not become official (with the approval of the Imperial Diet) until 1708, in the person of Ernest Augustus's son, George Louis.
In the Convention of Klosterzeven it was agreed that Hanover should be neutral with large parts of the Electorate occupied by French forces.
George II subsequently revoked the convention, and the re-formed Army of Observation counter-attacked and drove the French from the Electorate.
Although the Holy Roman Empire was dissolved in 1806, George III's government did not consider the dissolution to be final, and he continued to be styled "Elector of Hanover" down to 1814.
The personal union with the United Kingdom ended in 1837 on the accession of Queen Victoria because the semi-Salic succession laws in Hanover prevented a female from inheriting the throne if there was a male descendant.