So, I have read two different AU where Byleth meets either Dimitri or Claude when they were children and they have inspired me to write my own.

The Dimitri's story is called "The Boar's Liege" written by Tacticiangirl.

Claude's story is called "A Million Dreams" written by doylesmom

Both can be found on Archive Of Our Own and they are much better stories than mine so I would recommend checking them out first before reading my dinky, little story.

Before I let you get to the story, two little of my head cannon's might need a little more explanation before you read.

One, Jeralt is afraid of the church finding him and taking his daughter so he a bit on the paranoid side.

Two, Crest appear as a mark on a person skin after their first awakening.

At the start of the story Byleth is 10 and Dimitri is 6 going on 7.

Alright that's the end of my notes, on wards to the story.

Wyvern Moon Year 1170:

The start of the Red Wolf Moon month was the beginning of the season when Giant Wolves and other great beast become more aggressive in a desperate attempt to find food. To better ensure the safety of its citizens the Holy Kingdom of Faerghus had decided to hirer mercenaries to better combat such threats. The Jeralt mercenaries had been selected to help defend the capital city given their leader's reputation.

Just outside the castle's walls a large, muscular man waited with a young girl, with short blue grey hair. The man stared at the closed gate before him with his lips tightly pressed into a thin line. The girl, on the other hand, stared at everything before her, absorbing her new surroundings. Her expression never showed a hint of her curiosity. Eventually her eyes landed on the man and she gripped his hand, drawing his attention to her.

"Hey kid," he said smiling down at her.

"What's wrong?" She asked, her eyes never leaving his.

"Nothing." His smile became strained and she continued to stare up at him. A sigh escaped him, and he picked her up, resting her on one of his arms. "Fhirdiad gets pretty cold in the winter. Are you sure you are going to be okay?"

She nodded at him. "You bought me my new coat, remember?" She pulled on her coat's collar to emphasize her point. Another sigh escaped him, he was about to say something when the gates opened, and a guard stepped out. He put his daughter down but made sure to hold her hand.

"Sorry for the wait Sir Jeralt-" the guard was able to say more before he was interrupted.

"Just Jeralt." Another sigh escaped him.

"Oh right, sorry. It took a while to verify the contract, but everything is in order you and your daughter now have permission to enter." With that said the gates were finally opened and the guard started walking forward to lead the two newcomers. Jeralt's lips tightened into a thin line again and he gripped his daughter's hand tightly, but she didn't seem to mind.

They followed the guard in for a bit before he stopped to talk with another soldier. The castle's walls might have been impressive but inside was a completely different story. The young girl's eyes took everything in as she inspected any person that crossed her line of sight and at all the hedges that were cut into interesting shapes and sizes, spurring on her curiosity more. She would have left to explore if it wasn't for her father's grip.

Feeling eyes on her, she whipped her head around to find the source, a bit away, in a gazebo tucked in behind some shrubbery she was able to spot a young boy, who quickly hide behind the pillar he was peaking behind from. Without thinking she took a step forward but a tug on her hand halted her. She looked up at her father that was watching the soldiers talking. She pulled at his hand, until he finally looked at her.

"Can I please go exploring?" she asked glancing back at the pillar and noticed the boy was peeking out again.

Jeralt followed her gaze before turning back to her. "I don't think-" he was able to say before it was his turn to be interrupted by the guard.

"It's alright, she may explore," the guard said before turning his attention onto her, "but you must stay in the gardens okay?" She nodded and he smiled at her before returning to his conversation.

"Kid," her father said, and she turned to face him and discovered that he had bent down so that he could be eye level with her. When he spoke again it was whisper that was only loud enough for her to hear, "now remember if you see any priest or people with this symbol," he paused to maneuver his neck so that she could see the symbol on it, "you run away, you got that?" The symbol had reminded her of a leaf with a line through its stem. Despite her father's best attempts, she could never see it as a bad symbol, because she always saw it as her father's. She especially liked it when it glowed right when her father did a particularly powerful attack. Once she nodded, he let go of her hand and she was about to take off before he spoke again. "Once the negotiations are done, we will return to the inn, okay?" She nodded at him again before she left.

She ran straight to the gazebo and startled the boy causing him to fall onto his bottom. Pale, blue eyes stared up at her and she was left more speechless than she normally was. She didn't realize eyes could be such a pretty color. She extended her hand out to the blond boy, he stared at it a bit before he eventually placed his hand in hers and she pulled him up.

"Hello," she greeted but he was silent. She rested her hands on her knuckles and folded her arms over her chest. She knew there were more to greetings, but she didn't know what to say. She never had to greet someone before, her father always did it and she only ever had to do was a simple nod or say hello, but she didn't know what else to do after that.

"Excuse me?" the meek voice broke her out of her thoughts. She looked at the boy, who had his hands clasped over his stomach, he quickly looked down. His hair fell into his face, shielding his eyes from her and she didn't like; briefly she debated on whether or not she should push his hair aside but decided against it.

"I'm sorry. Did you say something? I was distracted."

"Oh um, I said my name was Dimitri Alexandre Blaiddyd." He looked up at her or more accurately her chin.

"Blaidid?"

"Blaiddyd."

"Blaydd?"

"Blaiddyd." She was going to try and pronounce his name again, but he stopped her. "You can just call me Dimitri."

She nodded. "Dimitri is a lot easier to say."

"What is your name?" he asked, now looking into her eyes. "Oh, that is if you do not mind me asking." He was quick to add.

"Byleth Eisner." He repeated her name and smiled. "But everyone calls me Kid."

"Kid? Is that not a little weird? Oh, I do not mean to be rude! I am sorry!"

She shook her head. "No, you're right. It is weird. You can call me something else if you want."

It was his turn to shake his head, but he did it with much more force than she had previously done. "No! If your friends call you that than," his voice started to trail off into a quiet whisper, "I would like to call you that too."

She rested her hand on her knuckles. The only ones who called her kid were her father and his mercenary group, were they her friends? Her father wasn't, of course, but she wasn't sure if friend was the right term, she would describe the other mercenaries. She broke her train of thought when she noticed his bright blue eyes staring at her. Nodding her approval at the nickname he smiled at her. A warm feeling settled in her stomach but before she could dwell on what it was, he was talking to her.

"So Kid, is this your first time at the castle?" She nodded yes. "Then let me show you around!" he grabbed her hand and began to lead her away. Her eyes drifted away from where they were heading and onto their hands. His hands were so tiny and smooth compared to hers or her father's, it was weird contrast, but she decided she liked it. Her eyes drifted back up and she noticed that he was leading her to the castle and so she stopped. "Is something wrong?" he asked turning to look back at her.

"I'm only allowed in the gardens."

He frowned but it was quickly replaced with a smile. "Okay, I will show you around the gardens instead." She didn't believe that she needed a tour guide, but she decided to let him do it, if only for him to keep his smiling.

Happily, Dimitri lead her thought the gardens sharing the little information he had. Byleth wasn't a plant expert but she knew enough to know when he was wrong or if he mispronounced something, but she didn't correct him. She liked the sound of his voice and didn't want him to stop talking.

The gardens were large, impressively so. She wished she could have come when everything was in bloom but seeing all the color of the leaves and watching them fall, still made for a pretty sight, even if most of the trees were already bare. She was content with just wondering around some more, but she knew her companion felt differently; as soon as the tour was done, he was ready to move onto the next thing.

"Let's play Knight and Princess!" he said as he showed off a large stick he found during the tour. "I will be the knight and you will be the princess, okay?"

"Shouldn't I be the knight? I know how to fight," she said blankly.

"No, you have to be the princess because you are a girl!"

"So? Why can't we play Knight and Prince instead?"

"No, you are pretty so you have to be a princess!"

"But I think you are prettier."

A blush spread across his face before he stopped his foot on the ground. "I am not pretty! I am strong! Besides, I found a stick to be a sword, so I get to be the knight!" She couldn't argue with that, the only thing she had on her was a dagger, but her father made sure that she knew that it wasn't a toy.

They decided, or mostly Dimitri decided, that one of the random garden's gazebos would be her castle, where she would wait for her knight to rescue her. She didn't really get it and was having a hard time imagining a castle, let alone the "monsters" he had to save her from. He would constantly stop whatever he was doing to explain to her what she was supposed to be doing; she never seemed to get it, but he didn't seem to mind.

Byleth always had a keen sense of her surroundings and of the time of day but when she looked up into the sky and discovered that it was already late into the afternoon she was lost. She had parted with her father around noon and she wondered if he was finished with his business and if he was looking for her. Fidgeting with the trim of her jacket she wondered if she should go look for her father, as she knew how worried he got but she also didn't want to leave Dimitri. She never realized before that moment how fun it could be to be with someone around her age and it left a bitter feeling. She often overheard some of her father's mercenaries mentioning how it was better to not make friends as losing them was just painful and she had followed that rule, not that it wasn't that hard to do with considering how uncomfortable she made people. But she broke that rule.

Dimitri had stopped what he was doing when he saw her just standing there. "Kid? What is wrong?" Her blue eyes met his clear ones; she didn't want to stop looking into his eyes. She opened her mouth to speak but another voice overshadowed hers. Jumping she quickly spun around to see the intruder and her hand flew to the dagger at her hip.

"Ah, Dimitri so this is where you have run off too?" said the intruder. He was a tall man with combed back, blond hair, and the same color of eyes as Dimitri. She could imagine that's what Dimitri would look like when he was older and had a beard. He shifted his gaze onto her and smiled. "Oh, and who might you be?"

"This is Kid!" Dimitri was quick to say. "She is my new friend!" He was smiling widely.

The man chuckled. "Kid? Is that your name?"

"That is her nickname!" Dimitri said before she could say anything. "All her friends call her that and since I am her friend I get to call her that now!"

More chuckling from the man. He bent down low so that he could be eye level with the children. "Tell me, do the people who call you that, are they much older than you?" She nodded yes and he gave her a knowing smile before shifting his attention onto the boy. "Sorry Dimitri, you cannot call her that."

Pouting Dimitri stopped his foot. "And why not?"

"Because older people are only allowed to call someone a kid." Dimitri continued to pout and cross his arms over his chest. "Look on the bright side you can give her a new nickname. Make your friendship a special one." His son's face light up at that.

"Can I really give you a new nickname?" she nodded yes, and he started to bounce with excitement. Almost immediately he started to list off names but would frown after each one, after a few seconds of this he huffed and stopped his foot. "I cannot think of one that I like."

"There is no need to rush it." A frown stayed on the young boy's face. "Well how about…" The man turned to her and stopped at the lack of name to work with.

"Byleth Eisner," she said picking up on the man's mild stress. She held out her hand for a handshake, as she had seen her father done numerous times. The man stared at her hand for a bit before laughing and shaking it. On the back of his hand she noticed a mark similar to her father's. If she were to briefly describe her father's mark, she would call it pretty (despite his probable numerous protest), while the man's would be powerful with all the sharp lines.

Noticing her stare the man held up the back of his hand for her to inspect it. "Are you interested in the Crest of Blaiddyd?" Her eyes flew to Dimitri, who shyly looked down.

"No," she said with a slightly shake of her head, "it just reminded me of my father's but his is more pretty."

"Is that so?" He took his hand back and gave her a soft smile. "Well then, it is your turn to come up with a nickname."

She looked at Dimitri, who was looking at her again, expectantly. "Blayid?"

Blaiddyd!" He stopped his foot. "And no, you cannot call me by my last name!"

It was her turn to list off some names but at a much slower rate. Every name she came up with was quickly vetoed by Dimitri, who was giving her vague descriptions of what he wanted his name to be like; like it had to sound strong and knightly as well as other similar things. The man quietly watched in amusement. Eventually they decided that they would have to think on their names a bit more.

"Kid! There you are!" Jeralt shouted as he made his way over to her. "You had me worried!" He picked her up and secured her in his arms before he realized that she was with two other people. "Your Majesty?! And Prince Dimitri?!" He awkwardly bowed with her in his arms. She glanced at Dimitri, who was looking down and was frowning.

"Are you really?" the king asked as he stood up.

"Aye, I'm Jeralt, Your Majesty. Captain of the mercenary group that you hired. I'm sorry if my daughter has done-" He was silenced by a raised hand from the king.

"Peace Jeralt, your daughter has done nothing but become friends with my son." With wide eyes the mercenary looked at his daughter. "I would like to continue to foster their friendship if you do not mind. I am sure my son feels the same." Clinging to his father's leg Dimitri nodded but he was still frowning.

"Your Majesty?" Jeralt's eyes shifted between the two people, before him. "Are you sure? I mean we are-"

"I do not judge people based on their backgrounds. And my son is often lonely being the only child in the castle. So, I would like to let their friendship grow. Of course, if that is okay with you." Jeralt's lips tighten into a thin line and he looked at his daughter who was watching the young prince.

"Should I call you Prince-" Byleth was able to say before Dimitri interrupted her.

"No! You can call me anything but that! You can even call me by my last name if you want!"

"Blaidid?"

"Blaiddyd." The frown on the prince's face finally gave away to a smile when he corrected her.

The king watched the children's exchange with a smile while Jeralt's held a more somber expression. His daughter wiggled around in an attempt to get him to put her down, but he refused. Holding his daughter tighter he shifted his weight around.

"Forgive me Your Majesty but we should be going," Jeralt said with a flat tone. The king looked into his eyes and nodded before picking up his own child.

"Ah, we should be too," the king said as he ignored Dimitri's protest. "It was a pleasure to meet you."

"The honor was all ours, Your Majesty." Another awkward bow and he was about to turn to leave when Dimitri called out.

"Byleth you will come tomorrow to play, will you not?" She looked at Dimitri before looking at her father. She could tell by her father's expression that he was against it, but she wanted to return. She glanced at the king, who was staring at her father with a difficult expression to read but when he noticed her gaze, he gave her a warm smile. Despite her father's wishes she nodded yes and was given the biggest smile from Dimitri yet. In return she felt the grip on her tighten as the farewells were said again.

With some distance created between the father and daughter pair and the royals, Jeralt spoke, "did you really make friends with the prince?" His tone was flat, and he didn't look at his daughter as he spoke.

"I'm sorry," she said, and the unexpected apology grabbed his attention. "I know mercenaries shouldn't have friends but…"

He stopped in his tracks to properly look at his daughter. To the untrained eye she was an emotionless being, but he knew better, as all one had to do was to look into her eyes to see what she was feeling and at that moment she was feeling guilt. It broke his heart and he rested his forehead against hers. "Oh Byleth… You're allowed to have friends," he said as he choked back a sob. "Forgive me for not allowing you to have one before now." She shook her head and awkwardly hugged his head. He took a deep breath to control his emotions before he spoke again, "hey, when we get to the hotel, let's have your favorite dish for dinner, okay?" While her face never reflected it, her eyes did as they shined with delight and he smiled at that.