I became the youngest prince in the novel is a Manga/Manhwa/Manhua in english language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

The Flosimar Chronicles of the Hero, a novel about the failure, not the success, of a warrior. “That sucks.” The emperor who had swallowed up the world closed his eyes and closed the book with a brief thought. But the moment I opened my eyes again, there were just a few lines in the chronicle. He had become a captive prince who faced death as soon as he appeared.