Although this strictly should cover the period 1811-1820 when George III was deemed unfit to rule and his son, later George IV, was instated as his proxy, the term is often more loosely applied to the years between 1800 and 1830.
As kempie said though, this included the 'Regency' period. The Regency Act came about in 1811 to provide a regent (an administrator of the state) if the British monarch were to be incapacited or in minority (under the age of 18).
Of course within the period 1811-1822 in Britain you also have....
Depression sets in (1811)
War with the US/Napoleons Russian campaign (1812)
Battle of Waterloo/Corn Law (1815)
Recession (1817)
Peterloo massacre (1819)
Death & accession of the Kings (George 3 and 4)
Irish famine (1821-23)
Greek war of independance (1822)