Regency era
The Regency in the United Kingdom is the period from 1811 to 1820, when King George III was deemed unfit to rule and his son, the Prince of Wales, ruled as his proxy as Prince Regent. On the death of his father in 1820, the Prince Regent became George IV.
The term Regency (or Regency era) sometimes refers to a longer period than the decade of the formal Regency. The period 1795 to 1837 (the latter part of the reign of George III and the reigns of his sons George IV, as Prince Regent and King, and William IV) was characterised by distinctive trends in British architecture, literature, fashions, politics, and culture. If "Regency" is being used to describe the transition between "Georgian" and "Victorian" eras, the focus is on the "pre-Victorian" period from 1811, when the formal Regency began, until 1837 when Queen Victoria succeeded William IV. If, however, "Regency" is being contrasted with "the Eighteenth century", then the period includes the later French Revolutionary Wars and the Napoleonic Wars.