The territory of Hanover had earlier been a principality within the
Holy Roman Empire, before being elevated into an Electorate in 1708.
(See prince-elector.) Hanover was formed by the union of several
dynastic divisions of the Duchy of Brunswick-Lüneburg, with the
sole exception of Brunswick-Wolfenbüttel.

Between 1714 and 1837 it was joined in a personal union, first with
the Kingdom of Great Britain and the Kingdom of Ireland, and then
from 1801 with the United Kingdom of Great Britain and Ireland. In
1803 the electorate was occupied by French and Prussian troops, and
following the Peace of Tilsit in 1807, its territories together with
territories ceded from Prussia was created into the Kingdom of
Westphalia ruled by Napoleon's brother Jérôme Bonaparte. French
control lasted until October 1813 when the territory was overrun by
Russian cossack troops, and the Battle of the Nations at Leipzig
later the same month spelled the definitive end to the Napoleonic
client state as well as the entire Confederation of the Rhine, after
which the House of Hanover was restored as rulers.

The prince-electors, formerly vassals within the Holy Roman Empire,
were elevated to monarchs of an independent kingdom at the Congress
of Vienna in 1814. This was conducted under the supervision and
advice of Baron Münster, head of the German Chancery in London.

During the British Regency and the reigns of the kings George IV
and later William, their younger brother Prince Adolphus, Duke of
Cambridge officiated as Viceroy of Hanover(1816-1837), representating
the King usually living in England. When Adolphus' niece, Queen
Victoria, daughter of his late elder brother Prince Edward, Duke of
Kent and Strathearn, succeeded to the British throne on 20 June 1837,
the 123-year personal union of the crowns of Great Britain (or the
United Kingdom of Great Britain and Ireland from 1801, respectively)
and Hanover (or the Electorate of Brunswick-Lüneburg before 1814,
respectively) ended. Adolphus' other elder brother became King as
Ernest Augustus I of Hanover and Adolphus returned to Britain. 

   

Kings of Hanover
Image	Name	Date	Notes
	George III	1814-1820	George III was mentally unfit during these years, and power was exercised by the Prince George of Wales (later numbered IV) according to the British Regency. In Hanover Prince Adolphus, Duke of Cambridge officated as Viceroy since 1816.
	George IV	1820-1830	Son of preceding. Regent 1811-1820, represented in Hanover by Viceroy Adolphus.
	William IV	1830-1837	Brother of preceding. Last monarch to rule both Hanover and the United Kingdom, represented in Hanover by Viceroy Adolphus.
	Ernest Augustus	1837-1851	Brother of preceding. His accession separated the crowns of Hanover and the United Kingdom, as the latter passed to Queen Victoria.
	George V	1851-1866	Son of preceding. Lost his territories to Prussia in the Austro-Prussian war.

Henry the Black, duke of Bavaria from 1120-1126, was the first of the
three dukes of the Welf dynasty carrying the same name. His son, Henry
the Proud, duke of Bavaria and also of Saxony, was the favoured candidate
in the imperial election against Conrad III of the Hohenstaufen. Henry
lost the election, as the other princes feared his power and temperament,
and was dispossessed of his duchies by Conrad III. Henry the Lion
recovered his father's two duchies, Saxony in 1142, Bavaria in 1156. In
1158 he married Matilda (1156-1189), the daughter of Henry II of England
and Eleanor of Aquitaine, and sister of Richard Lionheart. Dispossessed
of his duchies after the Battle of Legnano in 1176 by Emperor Frederick
I and the other princes of the German Empire eager to claim parts of his
vast territories, he was exiled to the court of his father-in-law Henry
II in Normandy in 1180, but returned to Germany three years later. Henry
died in 1195.

His son Otto of Brunswick was elected king and crowned emperor as Otto IV.
His grandson Otto the Child became 1235 the duke of a part of Saxony, the
new so-called Duchy of Brunswick-Lüneburg, and died there in 1252. The Welf
dynasty of Brunswick-Lüneburg would continue to rule in Hanover until the
defeat of George V of Hanover, Austria's ally in the Austro-Prussian War
when he was dethroned the Hanover annexed by Prussia. In 1692 the head  
of the cadet Calenberg line was raised to the status of an imperial elector,
and became known as the Elector of Hanover. His son, Georg Ludwig,
inherited the British throne in 1714 as a result of the Act of Settlement
1701. Members of the Welf dynasty continued to rule Great Britain until
the death of Queen Victoria in 1901; in Britain they were known as the
House of Hanover.

Hanover itself was raised to a kingdom in 1814, but was annexed by Prussia
following the Austro-Prussian War of 1866, in which Hanover had sided   
with Austria. The senior line of the dynasty ruled the much smaller Duchy 
of Brunswick-Wolfenbüttel. This line became extinct in 1884. Although the  
Duchy should have been inherited by the Duke of Cumberland, son of the last 
King of Hanover, suspicions of his loyalty led the duchy's throne to remain
vacant until 1913, when Cumberland's son, Ernst August, married the daughter
of Kaiser Wilhelm II and was allowed to inherit the duchy. His rule there
was short-lived, however, as the monarchy came to an end following the First
World War in 1918. The Welf dynasty continues to exist. Its current head,
Ernst August, is the third and present husband of Princess Caroline of Monaco.