A/N: This fic is based on/set in astroize's Middle Ages Supernatural AU on Tumblr. All credit for the world she created goes to her, I'm just playing in it. I took a few liberties with her timeline, though. I suggest you have a little look through her artwork to get a feel for the world, but this fic should be able to stand alone without the need for copious back story.
Also, I suck at titles, so this is named 'Primus' because it's the first time Dean and Cas meet, and I like Latin, and Latin fits the era and world.
Enjoy!
Primus
The great hall was eerily quiet the morning the angels were to ride out with the king's troops to push back the encroaching armies of Gehenna. Dean sat alone at a long dining table in the largest room of his father's castle, staring despondently into his porridge. He could hear the bustle of activity out in the courtyard – peasants rushing everywhere, the faint clatter of shifting plate armour, the gruff baritone of the castle's marshal – but it was muffled by the thick stone walls, and somehow managed not to disturb the air of silence in the hall.
It was likely to be a reasonably lengthy campaign; King John did not expect to return to the capital until harvest at the earliest. The past few weeks had had the city in a flurry of activity, gathering provisions enough to keep an army fed and clothed and watered on the long trek down to the borderlands. The peasants' excitement grew with the arrival of the militia from Caelus, the unearthly visitors like something out of legend. Their enormous wings marked them out for anyone who cared to look, and most of the angel-knights seemed not to shy from the attention they received. Two of their most senior commanders – Dean was unsure of their proper titles – had eaten with Dean's family at the head of the great hall at each meal, his father laughing and joking and generally treating them like very old friends. One of them – Gabriel – seemed to derive great joy from mercilessly teasing Dean at any opportunity. The archangel treated him like a child, an idea the king apparently wholeheartedly agreed with.
Dean had begged and begged his father to let him join the army on the battlefield, but the king had merely clapped him on the shoulder, and told him "Do not be so hasty to ride to war, Dean. The time to prove yourself will come. You are young yet." Dean privately thought that fourteen was more than old enough to put his swordsmanship to work, but simply acquiesced to his father's will with a scowl. The king's mind could not be changed once it had been made up. It was one of his greatest attributes and severest shortcomings, Dean's mother often liked to say.
With a sigh, Dean lifted another spoonful of the sodden oats to his mouth. He was in no hurry. There would be no training today, just a celebration of the impending successes of the campaign. If he was lucky, he might be allowed to go out for a ride, but not until long after the troops had left. His mother would probably make him practice his penmanship this afternoon, and he never got out of history lessons with Master Robert. Giving another put-upon sigh, Dean slumped to the side and rested his head on the table beside his bowl. A few moments later, though, the big wooden doors that led further into the castle swung open, and Dean lifted his head to see who was arriving.
Sam was walking down the hall towards him, wolfhound yearling and enduring tag-along Jo at his heels.
"At last!" he all but shouted. "I've been looking for you everywhere. Father's about to ride out, and Mama said we have to be there. She told me to find wherever you were sulking and make you come."
Dean scowled. "She did not."
"Well, she might as well have," Sam replied with a grin. Jo giggled from behind her hand. Dean glared at her. "Come on," Sam went on. "We're not going to see Father for six months. You really don't want to say good-bye?"
"No, I'll go," said Dean. Refusing to see his father off because he wasn't allowed on the battlefield yet was no way to demonstrate his maturity. He pushed his bowl away from him and met Sam and Jo at the bottom of the dais, flicking Sam's ear as soon as he got close enough.
"Ow!" Sam exclaimed, rubbing his ear.
"That's for saying I was sulking," Dean told him, smirking.
Sam gave him a half-hearted push, but grinned back at his big brother.
The courtyard was filled with people, and Dean had to stand on his toes and crane his neck to see where the head of the procession was. His father was standing by his big roan gelding speaking animatedly to Michael, the other high commander of the angel-knights.
"He's over near the gates," Dean said to Sam, before looking around for Jo, who was picking some flowers from a nearby garden bed. "Come on, Jo," he called, holding out his hand. After snapping off one more bloom, the little girl skipped over to the tawny-haired prince and took his hand.
"What have you got those for?" Dean asked as he began wending their way around the outside of the crowd, Sam and his dog following behind.
"To give to someone," she replied with a big smile that showed off her missing baby teeth.
"You mean a knight? Aren't you a little young to be giving out tokens?" Dean asked sceptically.
"'Course not!" Jo shot back happily. "Mama says it's always a lady's job to help 'spire courage in menfolk who're going off to fight for us."
"But you're not..." Dean trailed off when he looked back at the small blonde girl and saw she was gazing at her little bouquet and looking very pleased with herself. He decided it didn't much matter, really. "Never mind," he said.
They were nearing the gates that led down into the township, so Dean gripped Jo's hand tighter and started pushing through the crowd. Once the people saw who was trying to get through a pathway opened up and they three children made it over to the king with little trouble. Jo hung back a way while the two princes talked to their father. John turned to his sons, his left hand resting lightly on the hilt of his sword.
"Good morning, boys," he began. "I'm glad you found me before we left." He ruffled Sam's hair. "I'll miss you both. Don't neglect your studies while we're gone. You'll be good, won't you?"
Both boys nodded, one a little more profusely than the other.
"Good." He kissed each of his sons on their foreheads, slipped his left foot into the stirrup and pulled himself up onto his horse. Settling his hands on the reins, he looked down at his eldest son and said, "Next time, Dean." Then he pressed his heels into the flank of his mount and the big roan started forward.
The king waved good-bye to his sons and little Jo, before turning to wave to the crowd more generally, inciting cheers from his people.
"Quickly, Jo," Dean said. "Which knight do you want to give your flowers to?"
Jo was already walking down the line of mounted knights, searching their faces for the man she wanted. Sam announced he was off to find their mother, and after nodding to his brother, Dean followed after his almost-cousin.
Suddenly Jo ran closer to the moving horses and extended her bouquet up to a dark-haired angel. The man reined in his horse and brought him to a halt, reaching down to accept the little girl's offering. He smiled slightly at her ecstatic grin, and placed his hand on her head for a moment while his dappled grey mare stamped her hooves.
"Okay Jo, come back now!" Dean called, worried she might soon find herself trampled underfoot.
The angel looked up at Dean, staring at him with bright, clear blue eyes, and briefly bowed his head. It seemed somehow odd that this ethereal creature should show deference to a prince who isn't even old enough to wield a sword against an enemy, and so Dean nodded back. One side of the angel's mouth quirked upwards before he looked away towards the head of the column and pressed his horse to move on.
Jo tugged at Dean's shirt hem.
"He liked it!" she said excitedly.
"Yes, I saw," Dean replied, slightly drawing out the final syllable distractedly as he watched the angel riding away. He was sitting with impeccable posture, his shadowy wings tucked neatly against his back and extending down either side of the horse's flanks. As Dean watched, he leant over to speak to the sandy-haired angel riding beside him, and was rewarded with a jovial laugh and a hearty slap on the back of his armour from his companion. "How do you know that knight, Jo?"
"Umm..." Jo said, her cheeks tinged pink and trying to hide a smile. She ducked her head and brushed a stray lock of hair behind her ear.
"Yes?" Dean coaxed, teasingly elongating the vowel.
"He... did me a service," Jo said, the elegant phrasing beginning to worry Dean. Jo only made efforts to sound like her mother when she was attempting to hide something substantial.
"Oh? What kind of service?" he asked.
"I- Well, I was in a hurry and I fell and he helped me up," she replied very quickly, her cheeks even redder than before.
Dean just looked at her.
"What, that's it?" he asked, half-incredulous, half-relieved that she hadn't gotten herself into some kind of mischief.
Jo scowled at him for a moment before lifting her chin and primly peering down her nose at him. Then, with an exaggerated 'hmpf!', she flounced away. Dean rolled his eyes. For such a little thing she certainly was a master of elegant indignation.
The column of knights were still moving past the onlookers, and Dean gazed idly towards the gates of the courtyard. Jo's dark-haired angel must have passed through by now, off to defend the borders of a kingdom he didn't belong to. There was every possibility that he could die on the battlefield, and never see his friends or family or home again. Were the glories of war alone enough to justify dying for a foreign king? Dean knew he would happily risk his life in defence of his people and homeland. That is what being king meant. But another? Allies or no, it was a powerful gesture to fight for the benefit of another kingdom.
The last of the knights passed by Dean, and the crowd folded in behind them, some folk choosing to follow the procession down through the township. The young prince turned and started towards the wide stone steps where he knew his mother – and probably brother – would be standing. She would be as teary-eyed as she always was when the king left on campaigns, fearing that he wouldn't return, but Dean knew he would. He always did.
He'd come home and assign Dean a new weapons master as usual, convinced that the last one lacked the expertise to train his sons. Dean hoped this would be the last time it happened, if his father was really serious about Dean riding out with him on his next military venture.
Dean ran up the ornate stone steps and kissed his mother on her cheek before starting towards the stables, intent on rubbing down Impala, his steady coal black mare, in the hopes that he would be allowed to take her out later on and get away from the extraordinary noise of the castle and all the reminders of his inadequate youthfulness.