With the only opening to the mountains being a vast opening in the south east the reserve was created when prince Hargrovian who was a very evil man built a fortress and wall to make sure nothing could get out of the valley. He at first used it to let prisoners out and then he and his sons would hunt them down for sport. When this grew boring he planned to set up a game in which the most powerful warriors in the land would enter and then he would hunt them, but before this could be done he died. With his death his son Otta Hargrove set about making it profitable through turning it into a contest between the Kingdom and principlaties.
In a secret known only to the Hargrovian's the center of the Hargrovian Arena is scientific center that was created as a means for Tek to study humans under a controled situation which for the period he studied them was within the mountains. Following Tek leaving he opened a hole in the mountain so as to let people inside, and then hid his facility in the center. Whether Tek did this in order for someone to find it or he simply was to lazy to hide it better is unknown, but the Hargrovian's discovered it and have used it to become a truly sadistic family obsessed with the hunt.
The origins of the Hargrovian Arena lay in a period exactly following the Fall of Numeron, and the creation of the Crater of Pontus. Tek used this as an oppurtunity to create an experiment on humans within this extremely isolated area. Tek used his vast technology to quickly design an underground facility from which he set up cameras throughout the entire valley within the mountain. With this in place he brought humans within the valley and once inside he would play games with them in order to see how they reacted to situations. For nearly a century he continued this experimentation with the last series of experiments bordering on homicidal in their purpose.
When Tek left he hid the entrance of the facility and then blew a hole in the mountain range so that people could enter the mountain. The reason for Tek opening the mountain was that he wanted to see what a human would do with this type of facility. He had the inside of the facility wired with cameras and then returned to Iceland.
As the crater of Pontus became populated with people, it was only a matter of time until someone entered the valley, and when the Hargrovian family entered with their Lord House of House Jilly they made their home there. For nearly two generations the Hargrovian's lived as servents of House Jilly within the valley, but at the age of 17 Tigris Hargrovian discovered the entry to Tek's facility. As he moved deeper into the facility he found he was lead towards a vast room by the turning on of lights. As he continued to follow the lights he entered a room with a box in the center, a light shined on the box and a voice whispered in his mind to open the box. When he opened the box he found inside a chest which when he opened was filled with gold. The ambisios Tigris told noone and over the course of the next twenty years he used the things he found in the box to become immensly wealthy. His final act was to kill by himself the entire House Jilly members after he burned their house down and then hunted them for two days within the valley. With complete dominance over the valley he paid the builders of Pontus to build him a vast fortress which would block the entrance to the valley.
With his fortress constructed he along with his children begin buying slaves from the markets in Pontus whome they begin bringing inside the fortress of Hargrove.
These slaves didn't last long as the members of House Hargrove began using them as human hunting targets, The Hargroves would release them into the valley where they would use trackers which they were constantly given in the box in order to find them once they had run away. This continued for the rest of Tigris's life as he and his children including his daughters all took part in these hunting raids. At the age of 63 Tigris went with his two sons on a hunt against a blind slave they had purchased. As they hunted the slave Tigris called off his two sons and decided to attempt the hunt without any tracker. Without the tracker he was still able to catch the slave and when he approached the blind slave, the old man begin torchering the man by making scary noises and pushing him over. In fact the slave was not blind and had simply played this way, and as the harassment continued the slave stopped pretending and killed Tigris by drowning him in the water.
When his sons found his body they then quickly barried their father before hunting and killing the slave. The two sons then fought eachother to the death, with neither suriving the fight. With their deaths Tigris's third son Otto took control of House Hargrove.
The Hunger Games
Otto Hargrove was even more sadistic then his father but he was not strong enough to kill all these people in the hunts his brethren took part in. In order to maintain control he decided to turn this into a game where others killed eachother and he was able to watch them do it.