Shining Armor is Twilight Sparkle's brother. He is the husband of Princess Cadance. Their marriage took place on April 21, 2012. He is the former Captain of the Royal Canterlot Guard, serving under Princess Celestia, and bears the title of Prince via his marriage to Princess Cadance. He works closely with the equestian Guardponies in his role as Co-ruler of the Crystal Empire.
He was born in Canterlot to Crescent Sparkle and Twilight Velvet. He loves both his parents very much but his closest family tie is to his little sister Twilight. Twilight’s reluctance to come out of her shell and make new friends led to him becoming her protector. A role he found he quite enjoyed leading to his desire to become a Guardpony. While not as smart as his younger sibling he passed the Guardpony academy entry exam with ease.
Prince Shining Armor is the head of the royal guards tasked with protecting Canterlot Palace and the Princesses in their person. He takes the job very seriously and does what he can even though he now resides in the Crystal Empire. He believes in a active guard rotating the ponies standing watch out once a week. The rotated guards get placed in more stimulating jobs for a couple weeks then they go back to standing watch.
Twilight, I can't help it! Someone needs to help Twitterponies Wiki by adding more information.