Mnemonic Device
Willy, Willy, Harry, Ste, Harry, Dick, John, Harry three, One, two, three Neds, Richard two, Henries four, five, six – then who? Edwards four, five, Dick the bad, Harries twain and Ned the lad, Mary, Bessie, James the vain, Charlie, Charlie, James again, William & Mary, Anna Gloria, Four Georges, William and Victoria, Edward, George, then Ned the eighth quickly goes and abdicat'th, leaving George, then Liz the second, and with Charlie next it's reckoned.
Explanation
This is a traditional rhyme to help you remember the English (and later British) monarchs in order, all the way from the Norman Conquest to today. It starts with "Willy, Willy" - William the Conqueror, who defeated King Harold in 1066 - and runs through Harry (Henry), Ste(phen), the three Edwards, Richard II, three more Henries, two more Edwards, Richard III ("the bad"), the two Henry VIIs and VIIIs ("Harries twain"), Edward VI ("Ned the lad"), Mary I, Elizabeth I ("Bessie"), James I, Charles I and II, James II, William and Mary, Anne, the four Georges, William IV, Victoria, Edward VII, George V, Edward VIII (who abdicated), George VI, Elizabeth II, and finally Charles III.
Also see: Working Wives Have Seldom Had Really Jazzy Hemlines, a shorter first-letter version covering William the Conqueror through Henry V.