Back in the old days, Twelfth Night reveling included having a King and/or Queen for the festivites - chosen, of course, by baking a coin or bean or small image of Jesus in the cake. The person whose portion included the prize became royalty for the occasion.
I've read that this custom has its origins in pagan practices but, really, it is so fitting for the Epiphany - manifestation - of Our Lord. The Kingdom that Christ brings is, in fact, one of reversals. The valleys are exalted and the mountains and hills made low:
Twelfth Night: Or King and QueenNow, now the mirth comesWith the cake full of plums,Where bean's the king of the sport here;Beside we must know,The pea alsoMust revel, as queen, in the court here.Begin then to choose,This night as ye use,Who shall for the present delight here,Be a king by the lot,And who shall notBe Twelfth-day queen for the night here.Which known, let us makeJoy-sops with the cake;And let not a man then be seen here,Who unurg'd will not drinkTo the base from the brinkA health to the king and queen here.Next crown a bowl fullWith gentle lamb's wool:Add sugar, nutmeg, and ginger,With store of ale too;And thus ye must doTo make the wassail a swinger.Give then to the kingAnd queen wassailing:And though with ale ye be whet here,Yet part from henceAs free from offenceAs when ye innocent met here.-- Robert Herrick (1591-1674)