After the his wife Elmar committed suicide, Jartran Radd had a relationship with another woman. They gave birth to Fennan out of wedlock. This was kept a secret from his brother Norrin. He remained on Zenn-La after his brother became the Silver Surfer.
He next came to be the lover of Shalla Bal, much to Norrin’s surprise. He believed that the Zenn-Lavians were growing lethargic and responsible and planned to reform their society. Through Shalla Bal, he would plan to change their once great society.
Fennan was killed in the Earth year 1947 by the Other, along with the other Zenn-Lavians. Galactus created a realistic hologram of Zenn-La and it’s people so the Silver Surfer could return one day. Eventually, the Surfer learned of this and accepted the reality that Zenn-La was no more.