He was first mentioned in L. Frank Baum's second Oz book, The Marvelous Land of Oz, published in 1904. Pastoria was removed from his throne by the black magic of Mombi, an evil Witch, and was succeeded as ruler by the Wizard. Eventually, Pastoria's daughter, the long lost Ozma, the last surviving heir to Oz's throne, was found by Glinda, the Good Witch of the South, and with the help of the Scarecrow, Tin Woodman, Jack Pumpkinhead and the Sawhorse, was made the rightful rule of Oz. (The Marvelous Land of Oz)
Oz History: Fairy Queens & Mortal Kings
Pastoria adopted Ozma when she was a baby fairy. (The Magical Mimics in Oz)
Pastoria was kind, but does not appear to have been a very powerful King, as the land of Oz was still inhabited by four Wicked Witches who had enslaved many people. The Wicked Witch of the West had a Golden Cap which allowed her to command her Winged Monkeys, who were slaves to the cap, while the Wicked Witch of the East used the magic of her Silver Shoes to keep the Munchkin people in bondage. The only ones who stopped them from completely conquering Oz were the two Good Witches: Locasta Tattypoo aka the Good Witch of the North, who lived with the Gillikins; and Glinda who lived in a ruby-red castle with the Quadlings of Oz.
At the time Ozma was restored to the throne, it was believed that Pastoria was dead. (The Marvelous Land of Oz) It was later revealed that Mombi had enchanted Pastoria and transformed him into a "Tora the Tired Tailor". He was later discovered and disenchanted, but he no longer had a desire to rule and was happy to concede rule to the Ozma, preferring to open and run a tailor shop under his own name. (The Lost King of Oz)
There are conflicting sources regarding Pastoria's father: Paradox in Oz (1999) reveals that he was King Oz, the same wicked King who drank from the Forbidden Fountain as described in The Emerald City of Oz. However, The Blue Emperor of Oz (1982) reveals that Pastoria's father was Ozroar, the first ruler of Oz.
There are conflicting sources regarding Pastoria's wife: Mr. Flint in Oz (1987) gives her name as Ozette and says that the Wizard used magic he obtained from Mombi to enchant her, and she was then given over to the evil magician Peeramyd. However, The Astonishing Tale of the Gump of Oz (2007) gives her name as Cordia and says that Mombi herself enchanted her.
Princess Ozma later said that all Ozian rulers were called "Oz" if male and "Ozma" if female. (Dorothy and the Wizard in Oz) The fact that her father had a personal name makes it unclear if he ever had the chance to actually rule as King before being captured by Mombi.
Other Versions of Pastoria
L. Frank Baum originally created the character of King Pastoria for a 1902 stage musical. At the start of the play, King Pastoria II has been banished from Oz and is working as a street car conductor in America, with a waitress girlfriend lover named Trixie Tryfle. By the second act, Pastoria is restored to his original place on the Emerald City throne. Nothing of the stage character but his name made it into Baum's books, and he is not mentioned by Baum again after Dorothy and the Wizard in Oz.
In Gregory Maguire's revisionist Oz novels Wicked: The Life and Times of the Wicked Witch of the West (1995) and Son of a Witch (2005), "Pastorius" was the widower of Ozma the Bilious, who died from an apparently accidental poisoning, and father to Ozma Tippetarius, who was approximately the same age as Elphaba. As Ozma Tippetarius was too young to take the throne when her mother died, Pastorius ruled as Ozma Regent until the monarchy was overthrown by the Wizard. Sadly, Pastorius died during his subsequent imprisonment.
In the Disney film Oz the Great and Powerful (2013), Glinda, is the daughter of the late King of Oz, who was mysteriously murdered. The King in this story is not named.
In Tarl Teleford's reimagined Hidden History of Oz, King Pastoria is heavily revamped. Here, he is the the younger and lazier brother to King Oz XVII, and assumes the throne after his brother's death. He refuses to offer aid to Glinda when the Witches revolt, and later allows Mombi to join his court as Lady Chamberlain. Unlike most depictions, he remains in power well after the Wizard arrives, the Emerald City (still under construction) being separate from his own palace in the capital of Oz.