It likely started with being the eldest of four children, but Pete has always had a natural ability to lead others. He has a presence that others trust, and the ability to see the big picture. This became one of his most important traits after being crowned High King. With the safety of Narnia entrusted to him, Peter's skills in leadership were utilized and sharpened daily for the length of the Pevensies' reign.
Watching Peter in battle, Lucy once observed that he moved so fiercely and quickly that his sword flashed like three swords. Even before being crowned King, Peter had formidable sword wielding skills. He was gifted the sword Rhindon by Father Christmas himself, and Peter fought with it in multiple battles throughout the years. As he grew to adulthood as the High King, he was well known as a gifted warrior.
As a ruler, Peter has well honed the art of strategy. While it's true that diplomacy was more in line with Edmund and Susan's strengths, Peter was better at seeing the grand scheme of things and strategizing the best way to achieve his means. Both in battle and in politics.
However when the war broke out in Peter’s twelfth year, his blissfully happy life began to change. The war began to infiltrate their lives everywhere. It was constantly discussed at school and among friends, it was everywhere in the news, and Peter could see it etched into the faces of his parents. When his father enlisted, Peter felt a complicated mixture of emotions: pride, fear, pressure to step up and be the man of the family. No one else would know it, though. Outwardly, he stepped up and assured his father that he would look after the family in his absence. He did his level best to do exactly that and keep things as normal as they possibly could be.
There was only so much he could do, however, and eventually air raids on London caused their mother to send the children away. Wanting to be a good example for Susan, Edmund, and Lucy, Peter did his best to paint their trip to Professor Kirke’s estate in the best possible light. Little did he know at the time just how drastically that house would change the course of his life.
While playing hide and seek one dreary afternoon, Lucy excitedly pulled her siblings together and explained to them how she had found herself in the magical world of Narnia after climbing through an old wardrobe she’d found. Assuming it was all a game or a joke, Peter didn’t take Lucy seriously and encouraged her to let it go. The following day the same thing happened again, yet this time Lucy claimed Edmund had been with her. Edmund quickly denied it, and Peter and Susan became increasingly concerned about young Lucy. After speaking to the Professor about it, however, they quickly realized they were perhaps putting their faith in the wrong sibling. One afternoon, while hiding from the professor’s housekeeper, all four Pevensies hid inside the wardrobe and found themselves standing in Narnia.
Peter was immediately furious with Edmund for making Lucy out to be a liar and elected Lucy to be their leader. She took them to Mr Tumnus’ home, only to discover that the faun had been arrested by the White Witch.
In an attempt to rescue Mr Tumnus, Peter, Susan, Edmund and Lucy set out to see what could be done. Along the way they met Mr and Mrs Beaver and learned more about Narnia and the White Witch, Jadis. They also learned of the prophecy that two sons of Adam and two daughters of Eve would one day sit on the thrones at Cair Paravel.
It was at this time that Edmund had slipped away from the others to join up with the Witch. The Beavers explained that the only one who could save Edmund was Aslan. Despite everything, Peter still wanted to protect and save his brother and decided they should set out to find the great Lion.
During this trip, the remaining Pevensies were visited by Father Christmas (a sign that Jadis’ magic was already beginning to weaken). Peter was gifted with a sword, Rhindon, and a shield. He took the presents extremely seriously, as he understood that they were serious items. From there, the siblings continued on their way until they reached Aslan’s camp.
Here, Peter showcased his bravery by using Rhindon to slay the wolf captain after he attacked. Aslan honored him by knighting him Sir Peter the Wolf’s Bane, and he became the first member of the Order of the Lion.
Peter commanded the initial formations of Aslan's Army during the Battle of Beruna, during which Peter personally dueled with the White Witch herself, until Aslan finished her.
The battle had been going ill, until Aslan returned to his army with Susan and Lucy, as well as every Narnian who had been turned to stone and kept in the castle by the Witch. Soon after, the battle was won, and the Narnians were victorious.
After the battle, Peter, Susan, Edmund, and Lucy were taken to Cair Paravel and crowned by Aslan to be the new monarchs of Narnia. Pete became High King Peter the Magnificent, Lord of Cair Paravel, and Emperor of the Lone Islands. The Prophecy of the Golden Age came to pass with the end of the Long Winter, and the Pevensies rule bringing peace and prosperity.
It was difficult work, of course, ruling. Peter in particular had a difficult time during the Ettinsmoor War, in which he drove away the Giants of the North.
Years later, the now adult siblings were stag hunting in the forest when they came across a strangely familiar place. They ventured back through the wardrobe, and found themselves once more in the house of Professor Kirke. Even stranger still, only a few hours had passed there, and they found themselves children once more.
The following year was one of the most difficult of Peter’s life. He was angry and lost. He was forced to return to being just a child after leading armies and ruling a country. He leaned heavily on his siblings during this time, soothing themselves by recalling their adventures in Narnia and holding whispered discussions of when they might find their way back again.
Their return happened unexpectedly after an emergency call from Prince Caspian. He had blown Queen Susan’s horn which pulled all four of the siblings back to Narnia once more.
Though it had been more than a thousand years in Narnia, Peter and his siblings quickly took up arms to assist Caspian defeat his unscrupulous uncle Miraz during the Narnian Revolution. After the battle was done, Peter formally passed authority to rule Narnia over to Caspian.
Having learned everything he needed to from the world, Peter was told by Aslan that he would not return to Narnia again. The news wasn’t easy for Pete to hear, but he accepted it with grace and humility. He trusted that Narnia would be safe in the hands of Caspian, and that Edmund and Lucy would one day return.
After returning back to his own world, Pete did his best to live his life there, while still keeping Narnia in his heart. He finished schooling and even studied under Professor Kirke for a time. It was during this time that Susan began to drift apart from her siblings. As time went on, Susan became more and more focused on her life on Earth and began to think of Narnia only as a game they’d once played. This truly broke Peter’s heart and after multiple attempts to bring Su back, Peter felt he could no longer keep trying.
Years later, when Peter was 22, he and the other seven friends of Narnia (Digory Kirke, Polly Plummer, Edmund, Lucy, Eustace Scrubb, and Jill Pole) were having a dinner party together when they witnessed a strange vision. They witnessed the current ruler of Narnia, King Tirian, who said nothing to them, even after Peter demanded he speak.
Once Tirian had disappeared, the group decided that something must be wrong in Narnia. Wanting to help, they decided it was best to try the magic rings that Polly and the Professor had once used to get into Narnia. They were determined to set things right there once more.
Peter and Edmund went to get the rings, and the others would meet them afterwards at the train station. Horrifically, as the train was pulling into the station, something went very wrong. There was an awful crash. Before Peter realized what was happening, he closed his eyes and found himself in another world completely.