Flash Sentry, an orange pegasus with a blue mane and blue eyes, worked under Princess Cadance and Shining Armor as one of their guards. It wasn't until after Twilight had gone through the portal that they had met. Twilight, being the Princess of Friendship and the relative of the Crystal Empire's rulers, often visited and would sometimes speak to him, wanting to see if he was anything like his human counterpart. To her relief, he was.
Flash was enchanted by her. It was strange to him, but he payed it no mind as they got closer. Eventually they confessed their feelings for one another and started dating. During this time Shining Armor got very protective over her and made his work load a lot harder. On occasions he would even threaten the stallion, warning him what would happen if anything bad happened to his little sister.
For a long time Twilight was busy with looking over Ponyville and solving friendship problems. When she wasn't busy with that she was with her friends. They rarely saw each other for quite a while, so instead they wrote letters every day not wanting to lose the connection they had. Flash couldn't take being so far away from her anymore, requesting to leave the Crystal Empire's royal guard and become the sole guard of Twilight. Shining Armor opposed at first, but ultimately agreed with Cadance to let him go.
When he arrived in town he flew to her castle, knocking on the doors. She was shocked to see him on the other side and very happy once he had told her the good news. From then on he joined her on missions, protecting her and escorting her to where she needed to go. A year after he moved in with her they got engaged and another royal wedding was planned.
Everypony in Ponyville and Canterlot came to the wedding, including some of the guards from the Crystal Empire. It was a joyce day indeed. They settled down and not too long after had their first son, Cosmic. He was a purple unicorn, much like Twilight. He shared his father's mane and eye color only differing slightly in the style of his mane.
SPOILER ALERT! DO NOT READ THE FOLLOWING IF YOU DON'T WANT TO RUIN THE STORIES FOR YOURSELF LATER ON! IF YOU DO, READ ON FRIENDS!
Cosmic was still only a foal when Flash was called away. It was hard for him to leave his wife and young one, but he had a job to do. Celestia had called upon him for a search and rescue mission. Twilight was upset, but understood that he needed to leave. Before he left they shared one last night together. After that he had to leave.
For some time they were able to communicate, but Flash was attacked and the communications ceased. Three months passed and Twilight found out she was pregnant. She was distraught and didn't know what to do. In a final effort to find him she left home in search for him alone. She found him along with the other missing ponies and stayed there with them.
She left magic signals and trails for the others to find her. Eventually they were freed from where they were and were able to return home. Some time passed and she had their other son, Dusk. Dusk was an orange pegasus with dark purple eyes and a blue mane. The top of his mane resembled his uncle's with the Sparkle family stripe. His colors matched that of his parents' with his mother's dark blue mane and his father's lighter shade being the color of his one stripe.
As stated before this is sort of like a history story for the characters I'm going to be writing about. It's actually more of a summary. I may do some one shots later or get further into their stories, but as of right now these will stand as their 'History one-shots'.