This particular thread of the Equestrian multiverse exists with a few timelines. However, the threads are commonly referred to as the Chess Game of the Gods, even though they resemble nothing anywhere close to a chess game.
The history for this Equestrian realm is quite a bit different. Many events happen that do not for many other, similar realms. Hopefully, this document shall give it form that others may understand.
Early History[]
After the planet itself, Equis, was created, the gods created the 'Perfect Race', one that possessed amazing strength, magic and speed. However, during their creation, Discord appeared and fiddled with the process, making them imperfect, in direct contrast to their name.
This tampering causes the splitting into the three Elder races over a long period of time. First came the dragons, who inherited the immense strength of the perfect race. Next came the cynogriffins, who inherited the amazing speed of the perfect race. And finally, with the last of the dying 'Perfect Race', came the alicorns, who held the vast reserves of magical power contained within the 'Perfect Race'.
Each Elder race, during their reproduction also slowly create lesser being of similar racial features. Cynogriffins spawn griffins, diamond dogs, hippogriffs and a number of other similar races. Alicorns give rise to all manner of equine and bovine races, including ponies, cows, minotaurs and zebras. Dragons do not degrade as much, spawning few other races, such as drakes.
The Evils, also caused by Discord's meddling, rose and started wreaking havoc, which drew the attention of the Wardens. The Evils consisted of a number of races and beings created to cause chaos and destruction throughout the world. Among them are the Trolls, who have yet to be completely wiped out and are still active in the world at present.
The Wardens are a group of highly technologically advanced, human dimension travellers. They left their own plane after failing to protect it in search of a new, more peaceful existence; instead they found Equestria overrun by demons and evil. They took to the fight and forced the demons back or captured them. These wardens created the various prisons around Equis, known as Tartarus. They eventually set themselves up as guards, knowing escape from the prison was only a matter of time for some of its prisoners.
A few hundred thousand years later, Tirek arrived, a centaur-like creature quite literally made of evil. He brings with him all manner of monsters, including a type of snake-being that uses the bodies of victims to implant eggs and reproduce. The Elder races fight Tirek and his lesser offspring, waging war on him and all the Evils but the Trolls cause havoc for the cynogriffins and ponies, preventing their full dedication to the war and causing the extinction of the cynogriffin race. The Wardens react, awakening from Tartarus and systematically exterminating the Trolls along with an incredibly angry Lauren Faust and Sleipnir, the oldest and most powerful members of the alicorn race.
The battle with Tirek continued, and the descendants of the cynogriffins, such as the Griffins and Hippogriffs, fought as though possessed, for revenge on the Tirek-spawn for destroying their proginators. With the help of an ancient griffin warrior, an ancient Diamond Wolf, an ancient platinum Dragon, and two others, they combined their powers to generate the first use of the Rainbow of Light, an incredibly powerful spell that uses the virtues of friendship as power sources. Thanks to the efforts of Megan, the leader of the Wardens, Firefly breaks the Seventh speed barrier and kills Tirek.
However, the horrid damage was done, many of the Elder races had dwindled to nearly nothing, and Chrysalis, one of the two Flutterpony queens, had been tainted by his dark magic, becoming the first changelings. This painful process began to spread, turning other innocent flutterponies into dangerous Changelings, driven mad by agony. Likewise, the eldest of the last three alicorns, Princess Nyx Nocte Everfree, became twisted into an abomination of darkness, the being known as 'The Nightmare'.
After the Great War[]
After the Great War, Discord reappears, and starts upending the world, systematically dwindling the numbers of the Elder Races to a scant few, including Bahamut, one of the first Elements of Harmony. As the original Elements are slowly killed, with the exception of Firefly, who has become technically immortal from time travel, their souls are reborn into gemstones that Luna, one of the three surviving Alicorns, sets into the magic artifacts we now call the 'Elements of Harmony'. She and her sister, Celestia, leave to chase down Discord, who brought their race to near extinction.
The remaining races, surviving dragons and descendants of the cynogriffins and Alicorns, spread across Equis, hoping to find solace in mundanity.
The events of the 'Hearth's Warming Eve' play commence, and, after Dream Valley, now known as the Changeling Wastes, is evacuated of all save the last surviving Flutterponies. Discord, ever the sadist, attempts to 'help' them by accellerating their painful transformation, driving them and their still weak queen to the brink of madness. He fled the ensuing battle having lost a tooth, with the Wardens re-awakening to contain the changelings in Tartarus until they can calm themselves and regain their sanity, something that takes centuries to complete.
In response, Chrysalis' sister, Pandora, takes her own changeling people and hides deep beneath the ruins of the unicorn kingdom.
The 'Second Generation' Elements of Harmony are born and found, with the now time-traveling Firefly serving as the Element of Loyalty, and they protect Equestria from many remnants of Tirek's dark magics, such as Grogar the Necromancer and the Tirek-spawn. After they grow old and die, Firefly timeshifts to meet Celestia and Luna, entrusting them with the Elements of Harmony, marking the two future-princesses as the thrid generation.
After some time, the Princesses finally corner Discord and, with some cleverness, are able to make him sit and wait, in pose, for the Elements of Harmony, with Discord believing himself invincible. Due to his overconfidence, Discord is turned to stone and eventually moved to the Castle of the Royal Pony Sisters in what is now the Everfree Forest.
After several hundred years, Luna is tempted by The Nightmare, seeking dominion over Equestria and the World, becoming Nightmare Moon. A terrible war is waged between Nightmare Moon and Equestria. This becomes known as the Nightmare Rebellion. Of note during this period is the existence of an earth pony simply known as The Doctor, who disappears mysteriously afterwards. Eventually, Celestia is forced to use the Elements of Harmony by herself to imprison Nightmare Moon on the moon for 1000 years. 500 years affter Nightmare Moon's imprisonment, Kuchen Pie, a unicorn inventor, is hired by Celestia to learn how to reverse the transformation and expell The Nightmare. However, his repeated failures drive him mad and he winds up creating a multitude of devices that, while useful, have horrifying side effects, and ends up creating the 'Arcanum E. Draconus', a spellbook made from various parts of once-living beings. Celestia responds by horribly killing Kuchen in a fit of blind rage, both at Kuchen's cruelty, and herself for being the cause of his madness.
15 years prior to 'Day 1' of the Chess Game, Nathan 'Omnius' Traveler is brought to Equestria as an Illvouru, better known as a 'Werehog'.
During this time, the newest generation of the Elements of Harmony are born and raised. On the 1000th celebration of the Summer Sun Festival, Nightmare Moon is released from her prison and temporarily removes Celestia to the sun. The new Bearers of the Elements of Harmony find the Elements, which had been left in the Castle of the Royal Pony Sisters after Celestia banished Nightmare Moon. The fourth generation of Bearers are able to use the elements to remove The Nightmare from Luna and free Celestia from her fiery cell. The lives of the bearers continue as normal, with the Element of Magic, Twilight Sparkle continuing studies in the 'Magic of Friendship', the basis for using the Elements of Harmony in Ponyville.
Day 1: Discord frees himself from his prison of stone and fights with the Elements of Harmony. During his short time outside of stone, Discord brings Echo the Diamond Dog to Equestria, breaking a hole in between dimensional barriers. The following day, other gods begin to send humans as pieces for power and whatever else the god in question feels like. During the following week, Celestia chooses a human to be a changeling, a currently unnamed god sends a human named Griffin to be a griffin, Somnambula, an ancient Equestrian godess, retrieves a human to be a Bast in the jungle, Deceit, god of, well, Lies and such makes a human into a timberwolf, and Cora, creator of the world's core, forms a massive iron construct to be the body for a human who has taken part in more than one chess game. Many others besides are introduced over the course of the game, some even being as much as a year and a half late in arriving.