The first, well technically the second, time they met was after the Seven Years' War. France had ceded almost all of its colonies to England and Arthur had just introduced the shy and still grieving boy to his other colony in North America. Blue eyes inspected the new arrival almost critically before they turned away to demand, "Why does he look almost exactly like me?" Immediately afterwards, Alfred started bugging Arthur for food and they forgot about the quiet new addition. A couple hours later, after Alfred finally remembered Matthew's existence again, he had declared in a loud voice, "Hey, Canadia! You have a hero for a brother now!" Before bursting into his signature laughter and dragging Matthew off into trouble. In the years that followed, the two grew very close, although Alfred still forgot where Matthew came from and mistakenly called him Mathias once.
Matthew quickly found out that his new "brother" was a very independent person, even for a colony, often mirroring the birds that flew in the sky with his inability to stay down for long periods of time. With him, Matthew discovered the joys of racing among trees after dark and trailing wolves and deer through the forest, in return, he taught Alfred to enjoy the snow and the thrilling excitement of sailing in rougher water. As they grew older, both found inexplicable happiness in wild horseback riding, throwing off English etiquette and lessons for the adrenaline of feeling wind whip their faces and seeing the scenery blur together into ribbons of color. Alfred drives Arthur insane though, and Matthew often hears the sharp, staccato sounds of their guardian's voice as he reprimands Alfred for grammar mistakes in speech or lapses in proper etiquette. Alfred is always uncharacteristically silent afterwards and sulks quietly in his bedroom before rejoining Matthew in some scheme or another.
They are both physically around the age of 15 when Arthur first fits them both with the blood-red uniforms of the British infantry. Alfred squirms and wriggles impatiently as his measurements are taken, pouting at Arthur when the elder tells him to stand still. In all honesty though, both can see that red does not suit Alfred and for some unknown reason, that scares Matthew. There's something he can't pinpoint in his brother that is growing, waiting and biding its time, looking for the correct time to strike and destroy. He blinks when Alfred asks him if he is doing alright and the feeling disappears as quickly as it came. That night, Alfred drags both Arthur and Matthew out of their warm house into the cool outside air, pointing toward the inky sky where there are thousands of stars glittering like diamonds. Arthur points out the important ones he uses for navigating the Atlantic Ocean and is about to teach them how to use the stars when Alfred stops him, "Teach later, Artie, I'd like to appreciate the beauty first before you change it into a tool for me to use."
Both of his companions are shocked to silence by the intelligent request, it doesn't last long though because Alfred is Alfred and soon, Arthur is being bombarded with questions about flying to stars and Matthew just lies in the grass and wishes that his brother would shut up. When Alfred does settle down into silence, Arthur almost immediately falls asleep out on the field exhausted from the questions and lack of sleep due to work. Matthew stays awake with Alfred, watching the twinkling stars and listening to his brother murmur the names Arthur had taught him. As the night gets colder though, they are forced back into the house, Matthew watches Alfred carry Arthur back in almost effortlessly; it's the first time Matthew sees exactly how tall and muscular Alfred has gotten.
…Man, I just realized exactly how fast Alfred and Matthew grew up physically. They kind of go from toddlers to full-blown teenagers in less than 5 years…mind blown.