They knew that all of Oz, including their own territory, was ruled by a beautiful Princess named Ozma, who lived in the splendid Emerald City; yet the simple folk of Oogaboo never visited Ozma.

They had a royal family of their own--not especially to rule over them, but just as a matter of pride.

Ozma permitted the various parts of her country to have their Kings and Queens and Emperors and the like, but all were ruled over by the lovely girl Queen of the Emerald City.
The King of Oogaboo used to be a man named Jol Jemkiph Soforth, who for many years did all the drudgery of deciding disputes and telling his people when to plant cabbages and pickle onions.

But the King's wife had a sharp tongue and small respect for the King, her husband; therefore one night King Jol crept over the pass into the Land of Oz and disappeared from Oogaboo for good and all.

The Queen waited a few years for him to return and then started in search of him, leaving her eldest daughter, Ann Soforth, to act as Queen.
Now, Ann had not forgotten when her birthday came, for that meant a party and feasting and dancing, but she had quite forgotten how many years the birthdays marked.