The Boy Who Lived

It is the 28th century. Global catastrophic events such as massive floods and pandemics, coupled with a century-long resulting event called "the great hysteria", have deeply affected human society. Governments broke, society fell into chaos, and essential resources became scarce. Most technology was lost, including electricity and firearms, as both the knowledge and the material necessary to build power plants or engineer sophisticated combat machines became far from attainable, while time rendered the old ones unusable. Local conflicts for resources ensued everywhere, so the desperate populace seeking protection, shelter and food formed small, isolated, fief-like societies all around the globe. Some communities were founded in the wild, while others opted for inhabiting the ruins of old cities, whose buildings began to serve a whole new purpose (for example, old parking lots began to be used as farms).

In this neo-medieval, post-apocalyptic world, society has achieved a greater stability and even inter-community trade has taken an important role, but culture remained a confused question. As basic survival and reproduction became the sole purpose of life for many, most people stopped to read, write, and engage in intellectual conversations for centuries. Humanity remembers very little of the "screen era", the period in which computers, movies and the like were widespread, and most of what is known about the past comes from distorted oral tradition and the little printed material that survived the great catastrophes, written in what are now perceived as ancient languages. Since they were found in numerous old languages on every corner of the world, two written sagas became widely familiar in this world: the Bible and the Harry Potter series. The origins of the first are relatively well understood, but the latter's are largely mysterious. Most people know that the Bible was the sacred book of an old religion called Christianity, a religion that for most of history was the world's largest but is now condemned by oral tradition as having been one of the main causes of the great apocalypse (although no one knows for sure exactly why). As to the Harry Potter series, the only thing known is that it was written by an obscure 20th-century writer named J.K. Rowling.

For the 28th-century uneducated people, the Harry Potter series proved much more enticing than the Bible. It is believed that this happened for two reasons: first, although still old, it was written in a much more understandable tone, probably because it is only a few centuries old and directed to a general audience, while the Bible is millennia old and full of complicated references to themes such as prophecies and genealogy, which were only relevant at the time they were written; and second, oral tradition said nothing bad about it. The hopeless, cultureless people needed a destination, a purpose, a meaning for their lives, and the Harry Potter books provided it to then. Soon, individuals who were familiar with the history of Christianity (as some documents about it have also survived) created a new cult centered around the figure of Harry Potter using Christian elements. Harry began to be venerated as "The Boy Who Lived", the one who survived death through his mother's love. Old churches were redecorated to worship the ancient magic, the seven Harry Potter books were divided into verses (just like the Bible), and a narrative was created in which Harry Potter and Dumbledore represent the forces of good and order, who fight Voldemort and his followers, the forces of evil and desire for power.

In a few decades, the Harry Potter cult turned into a widespread religion. For some, the events described in the books really happened, everyone can be a descendant of the ancient wizards, and the religion's goal is to help one develop his or her inner magic. For others, the events described were allegories referring to themes such as the fight between good and evil, and magic exists only in a spiritual way. In either case, this new religion, called Potterism, became the pivot of this new society, immensely influencing its culture and philosophy.

Language
Several constructed languages designed to international auxiliary use, such as Lojban, Esperanto and Kotava, became widely popular by the late 21st century. Easy to learn and practical to use, they have largely replaced natural languages since then. By the 25th century, natural languages that once dominated international culture and commerce, such as English, French, Chinese, and Spanish, had virtually no more native speakers, and were already considered ancient languages by the early 28th century.

The constructed languages that began to dominate the world eventually acquired characteristics similar to those of the "ancient" languages, evolving naturally with time and producing descendants. Today, there are three major language families:
 * Esperantic languages (descended from Esperanto and Esperantidos)
 * Lojbanic languages (descended from Lojban)
 * Kotavic languages (descended from Kotava)

Many fiefs also developed their own constructed languages, which reflected elements particular to their culture.