The breed that would come to be known as the Snjorrir originated in a world called Alderann - an alternate dimension that can be accessed by people of modern day Earth via rips in the dimensional thread known as portals. It's believed that the only true native horses of Alderann were the talking horses of Caer Niser, or 'Caerians'. It is believed that the first ancestors of the Snjorrir breed of Alderann were a herd of Snjorsturs that accidentally stumbled across a disused portal in the icy wilderlands of Earth, that brought them out into Alderann.
As they were the first horses that could be easily domesticated (the Caerians being too proud and too stubborn), they became the backbone of what would later become the Snjorrir breed. Later infusions of Caerian blood and more Snjorsturs found wandering in the wilds led to a refining and narrowing of the breed.
Creating the Perfect Warhorse
It was then the dark denizens of Shadowvale that began their experimentation to create the perfect creature of war. They had once tried to tame the dragons, to no avail. So, they sought to bring out dragon-like tendencies in their horses. Their experiments were many, varied, and often horribly cruel. Initially, they forced prisoners of war to torture Snjorrir mares, in order to instill in the the mares a hatred of foreign people. The mare would then pass her behaviour down to her foals, and from there, the breed typing only became more concentrated. The fiercest and the most aggressive stallions and mares were bred extensively. Those deemed weak or too friendly were either cast away into the wilds or killed.
The result was a race of horses that were fierce, very xenophobic, mistrustful of strangers, and unafraid of getting their teeth and hooves bloody.
The current king of Shadowvale, King Alzeron, was a ruthless tyrant, but a smart one. He knew that such a breed would one day become uncontrollable, so he ordered a halt to the current practice of breeding for ferocity alone. Instead, he had breeders begin crossing back to the more protective and loyal manifestations of the breed, to ensure that no matter how deadly or fierce the horses became, they would always respond positively to their masters and riders. This crucial element is what finally solidified the Snjorrirs as the perfect instruments of war.
King Alzeron of Shadowvale was known for his many sons - 7, to be precise. The first 5 made up his inner circle - trusted princes whose dark minds and hearts matched their fathers in greed and ambition. Situated as generals at the head of their father's army, they were a force to be reckoned with.
The 6th son of Alzeron was a peacekeeper at heart, born with light in his soul. He never approved of his family's actions, and would often speak out, trying to turn them back to reason. He protected and raised his youngest brother, taking advantage of his father's preoccupation with conquering other regions to focus his efforts on his younger brother. When his father learnt of how his 6th son was influencing his youngest, he put out an order for his execution, however the prince fled before the order could be carried out. However the damage had been done. The youngest son now saw the error in his family's ways, and saw the King's ambition as a sign of weakness and the desperation of an aging tyrant. He became the thorn in his father's side, ever disrupting his father and brothers' carefully laid out plans, halting progress from within. Nowhere near as good-hearted as his exiled older brother, he saw no wrong in conniving and cheating to make his own plans come to fruition.
Which leads us back to the story of the Snjorrirs, and their subsequent re-introduction to Earth. The youngest prince, Tzarik, realised that though the strategising minds of his family was what gave the Shadowvalian army its direction, it was the horses that made up the cavalry that brought the army its strength. As such, he sought a way to cripple his father's strength by removing access to his precious war horses.
Knowing the old legends of how the Snjorrirs came to be, he followed leads around, questioning old historians and even holding an audience with the Caerians in order to discover exactly how the Snjorrir ancestor-horses came to exist in Alderann. In doing so, he learnt of the existence of portals, and Earth beyond that. With months of work, he finally managed to locate foreign travellers from Earth, following them around until they finally led him to one of these portals. It was then that he made history, becoming the first creature of Alderann ever to leave his own dimension.
After meeting with the denizens of Earth on the other side - members of an organisation known as 'Spaves', he drew up an agreement with their leader. He would use their organisation as a throughpoint, a place to hold the horses of the Shadowvalian army before distributing them to safe locations around Earth.
It is in this way, with the steady leaking of the Snjorrirs out of Alderann, that the might of the dark conquering force of the Shadowvalians is finally being thwarted.