"Alternate History" (also known as allohistory, counterfactuals, or simply AH) is a genre of literature that describes factual historical events, and then branches into fiction. Traditionally, these works have been aimed at an adult audience. Hilary Mantel's 2010 Wolf Hall, for example, explores Henry VIII's drawn out divorce with Catherine of Aragon and marriage with Anne Boleyn, but then inspects a somewhat fictional portrayal of Thomas Cromwell, here a blacksmith's son who becomes the king's right-hand-man and ultimately fixes Henry VIII's marriage.
Children's historical fiction has been around in a similar fashion. Picture books and Early Reader chapter books about wars, famine, and slavery have been written for children as supplemental history lessons. For instance, Cynthia Harnett's The Wool Pack looks at 15th century English wool traders and features "sympathetic child characters who navigate the bewildering politics and restrictions of their...time in [an] utterly absorbing story," according to The Guardian. Or, a more accessible example: Disney's version of Pocahontas. Let's be real - John Smith got a little too much credit.
But the YA trend is very new. While dystopian fiction has dominated the young adult world for several years, some critics agree that YA alternate histories are the new big thing. A panel of YA AH authors - Scott Westerfeld, Holly Black, and Cassandra Clare - met in 2009 to discuss the up-and-coming genre.
Westerfeld has penned over 20 science fiction novels. His most recent Leviathan trilogy portrays a different kind of World War I that explores Darwin's ideas on human selection and the subsequent conversations on genetic engineering through robots designed specifically for war. When asked about the attraction to AH, particularly for teens, Westerfeld explained in a Boom Tron article that "one of the chief pleasures of alternate history is being able to recognize so much of the world as familiar with one jarring thing that's changed." For the Leviathan trilogy, factual history takes a drastic turn when Darwin not only theorizes evolution but also discovers DNA in the 1860s, which leads to a series of different fictional events.
Similarly in Ben Jeapes' The New World Order, a familiar English civil war rages throughout the books pages, but the use of repeater rifles and machine guns make an early entry into history, followed by an obviously sequential alien invasion. As such, facts turn into fiction while still holding the semblance of truth.
Many YA authors have embraced the new genre, so a slew of new AH books are on the way. Taylor Anderson's Iron Gray Sea will be released in July, followed by Harry Turtledove's Coup DdEtat in August, just to name a few.
Vampires and post-Apocalyptic America will continue to fill library shelves, but it looks like alternate histories might make it into just as many readers' hands.