Romulus and Remus were kidnapped when they were very young and were left by the Tiber River to die. A wolf saved the brothers and took care of them as if they were her own wolf pups.
When the shepherd discovered Romulus and Remus, the wolf would not leave their side. The wolf did not attack the shepherd but refused to leave the brothers alone.
When the brothers learned that they were of royal blood, they left the shepherd to go to their family's kingdom. The wolf followed and was not allowed in the kingdom. Instead of abandoning the wolf, Romulus and Remus headed back and found a piece of land that they would build a kingdom on. It was the land near the Tiber river, where the brothers were found by the wolf.
Romulus and Remus were about to fight right after they finished building their town because they couldn't decide who would be the king. For years, all they wanted was power but now only one could have the power. They didn't want to hurt each other so it was up to the wolf to decide. The wolf chose Romulus but Remus would help make decisions.
The wolf was mad at Romulus and Remus because they used her to carry supplies to build the town. She decided it was time to stick up for herself and threatened to leave the brothers if they didn't give her power. Romulus and Remus couldn't live without the wolf so they had no choice but to treat her better.
Although Romulus was still the king of the new town, Romulus and Remus had to treat the wolf like a queen. The new town was called Rome after Romulus.