How did the Silver Surfer begin?

Answer 1

The Silver Surfer began as Norrin Radd, an astronomer on the planet Zenn-La. In order to save Zenn-La from the planet consuming Galactus, Norrin agrees to become herald for Galactus and seek out planets for Galactus to destroy.

Galactus turns Norris into the Silver Surfer by imbuing him with a portion of the Power Cosmic. The Silver Surfer serves Galactus, eventually summoning Galactus to Earth.

The Silver Surfer meets the Fantastic Four and Alicia Masters on Earth and rebels against Galactus. Galactus is driven away from Earth but, before he leaves, confines the Silver Surfer to Earth with an invisible barrier that affects only him.