In 1714 George I, prince-elector of Hanover and a descendant of King James VI and I, assumed the throne of Great Britain and Ireland, marking the beginning of Hanoverian rule over the British Empire.

At the end of this line, Queen Victoria's death in 1901, the throne of the United Kingdom passed to her eldest son Edward VII, a member of the House of Saxe-Coburg and Gotha, through his father Albert, Prince Consort.

The last reigning members of the House of Hanover lost the Duchy of Brunswick in 1918 when Germany became a republic and abolished royalty and nobility.

The 1866 rift between the houses of Hanover and Hohenzollern was settled by the 1913 marriage of Princess Viktoria Luise of Prussia to Ernest Augustus, Duke of Brunswick, the last king's grandson.

At the end of the Thirty Years' War, the Peace of Westphalia (1648) awarded the Prince-Bishopric of Osnabrück alternately to a Catholic bishop and to a cadet branch of Brunswick-Lüneburg.

[4] Since the treaty gave cadets priority over heirs and reigning princes, Osnabrück became a form of appanage (in alternation) of the House of Hanover.

The Duke of Cumberland's eldest son died in a car accident in 1912; the father renounced Brunswick in favour of his younger son Ernest Augustus, who married the Kaiser's daughter Victoria Louise the same year, swore allegiance to the German Empire and was allowed to ascend the throne of the Duchy in November 1913.

Since the later king Ernest Augustus had been created Duke of Cumberland and Teviotdale and Earl of Armagh by his father George III in 1799, these British peerages were inherited by his descendants.

[6] On 29 August 1931, Ernest Augustus, Duke of Brunswick, as head of the House of Hanover, declared the formal resumption, for himself and his dynastic descendants, of use of his former British princely title as a secondary title of pretense, which style, "Royal Prince of Great Britain and Ireland", his grandson, the current head of the house, also called Ernest Augustus, continues to claim.

[7] He has the right to petition under the Titles Deprivation Act 1917 for the restoration of his ancestors' suspended British peerages Duke of Cumberland and Teviotdale and Earl of Armagh, but he has not done so.

His father, another Ernest Augustus, did, however, successfully claim British nationality after World War II by virtue of a hitherto overlooked (and since repealed) provision of the Sophia Naturalization Act 1705.

[8] According to the decision taken by a court of the House of Lords, all family members bear the last name Guelph in the UK and are styled Royal Highnesses in their documents.