Dorothy Gale is a fictional character created by the American author L. Frank Baum as the protagonist in many of his Oz novels. She first appears in Baum's classic 1900 children's novel The Wonderful Wizard of Oz and reappears in most of its sequels. She is also the main character in various adaptations, notably the 1939 film adaptation of the novel, The Wizard of Oz.
In later novels, the Land of Oz steadily becomes more familiar to her than her homeland of Kansas. Dorothy eventually goes to live in an apartment in the Emerald City's palace but only after her Aunt Em and Uncle Henry have settled in a farmhouse on its outskirts. Dorothy's best friend Princess Ozma, ruler of Oz, officially makes her a princess of Oz later in the novels.
Source : Wikipedia