The Ruins of the Kingdom are the remains of the Ancient Kingdom from DunBroch's oldest legend, as it teaches and reminds people to never let their selfishness and pride get the better of them and what it can lead to. Merida (along with the rest of the people of DunBroch) had thought that the kingdom and its story were just a legend, until the Will O' the Wisps led her and her mother to the ruins.
The kingdom was once ruled by a wise, kind King that was well beloved by his people and his four gifted sons. The youngest was wise. The third was compassionate. The second was just. And the eldest brother was strong. However, he mistook great strength for character.
But one dark autumn, the king grew ill and passed away. Rather than giving the eldest all the inheritance, he divided the rule among all of his sons, believing their gifts combined would make the kingdom even greater. However, the eldest son, feeling disgraced and filled with greed and arrogance, refused to accept this and started a war against his younger brothers after they refused to give total rule of the kingdom to him.
Even when the prince and his brothers were evenly matched, the prince went to a witch that would give him a spell to give him the strength of ten men by offering her his signet ring, and she gave him the spell in a drinking horn, but warns him of making a choice: either he must make amends by reconciling with his brothers or he will suffer a fate trying to fulfill his goal.
When the prince brought his brothers before him by staging up a false truce, to their protests, he drank the spell, which gave him strength tenfold, but to his surprise, in the form of a great black bear. While he would potentially have broken the spell by apologizing to his brothers, the prince instead accepted his new form and slew them in cold-blood. He then tried to get his army to rule the kingdom, but they saw only the dreaded beast and turned against him. The bear then attacked his former men, slaughtering a great many of them while the rest fled the kingdom in terror. With the armies of the brothers fractured, the kingdom collapsed into darkness and ruin. The bear, now being named as Mor'du for his history, ended up roaming around the area, his once human consciousness now lost forever because of favoring power over the bonds of family: and the ruins became the beast's lair.
Through the years the kingdom and its name were forgotten, but the story of its fall became one of the highlands well known legends.
"Once there was an Ancient Kingdom. Its name was long forgotten that was ruled by a wise King that was well beloved, and when he grew old he divided the throne between his four sons, so that they could be the pillars on which their land rested on. But the oldest son wanted the throne all to himself and the Kingdom fell, leading it into war and ruin."
Merida believed the kingdom and its story were just a legend and moaned as her mother retold it to her, as Elinor tried to tell her daughter that legends ring with truth and that she'll end up like the oldest son if she doesn't get her pride go and let the lords' sons win her hand.
After Merida met the same witch and gave her mother the same kind of spell and the two were trying to undo it, the Will O' the Wisps led them to ruins. Merida wasn't sure who once lived there until she fell into the old throne room and saw the four stone thrones and the split stone carving of the brothers; she realized that she wasn't the first one to use the spell, the ruins are the remains of the kingdom from the old legend and that the prince that the witch told her was the oldest son and that the spell turned him into Mor'du.
After Merida put the peaces together, the beast woke up and tried to catch her, but Elinor got her daughter out of the ruins and the two ended up in Ring of Stones. When the two went back to the Castle (so they may fix the family tapstry and undo the spell), Merida reminded her father and the lords of the legend: as Merida told them and how their own kingdom is still young, and that their stories are not yet legends and how they put their hatred for each aside so they may defend their land and bring it together, she realized her mistake and what her selfness would of led to and that legends do ring with truth.
- The last land that the Stone Ring brings Merida to in the video game resembles ruins, infect they may achaly be the ruins, as it was the place where Merida faced and battled Mor'du.
- If you take the spell, the necklace that Merida used to pay for it, the DunBroch Family Tapestry and Merida going agents her mother's wishes, it was like Merida was repeating the kingdom's story. But Merida understood her mistake and fought to fix and turn her mother back, before "their" kingdom could suffer the same fate.