Prince Elias was just a baby when the ship that was carrying him and his mother, Queen Alicia, crashed on the Floating Island (now called Angel Island). The Brotherhood of Guardians (Knuckles' ancestors) took him in and raised him in Haven. He was never taught the politics of royalty, so all he ever wanted to do was find adventure. In Sonic #68 he returned to Mobotropolis, where Sally met him for the first time. She was confused and annoyed at their father for keeping her own brother a secret from her, but over time they got to know each other and became friends.
When King Max was injured while on a mission, he put Elias in charge of Knothole Village, when everyone knew that Sally was the more experienced candidate. Under pressure from his father and from Geoffrey St. John, Elias eventually gave up and ran away. He took up residence in a forest, married a girl named Meg, and together they have a daughter, Alexis.