Kent Nelson was the son of archaeologist Sven Nelson and, around the year 1920, the two of them were exploring the Valley of Ur in Mesopotamia when they discovered an underground pyramid. It contained Nabu, an ancient immortal from the planet Cilia who had been held in suspended animation for thousands of years. Kent released him, but the lever accidentally unleashed a poisonous gas that killed his father. It would later be revealed that Nabu engineered this situation to gain a new host. Nabu decided to mentor the young boy in the secrets of the universe, giving him incredible powers through total molecular control and taking his grief away from him. He would serve as an agent of the Lords of Order in their never-ending battle against the Lords of Chaos. Having finished his training, Nabu gave him an amulet, cloak and helmet to become a champion of good as Doctor Fate. Kent would go on adventures as Fate, although Nabu's spirit would always guide him through the helmet and he'd awaken with little memory of his own exploits. He would go on to meet a beautiful college student named Inza Cramer while traveling through Alexandria, and she would become his long-time romantic partner and confidante. His first battle was against the evil sorcerer Wotan, who struck at him through Inza using an agent named Thomas Frawley.
Dr. Fate's first encounter with a hero of that era was the Spectre, the wrath of God. Together they destroyed a military gateway to a netherworld of demons. It was World War II and America was pulled into the war, Dr. Fate and many other mystery men help defeat an assassination attempt of President Roosevelt's life. At Roosevelt's request, they formed the Justice Society of America.
During this time, Kent found the helmet becoming more and more possessive of him, so rather than abandoning his battle against chaos, Kent created the half helm. Although Kent's powers were severely limited, he still had the ability of flight, invulnerability and super strength. However, Kent donned the helmet one last time in order to find the missing Spectre. Dr. Fate discovered that the Spectre was under the control of Kulak and in a titanic battle with the Spectre, he was defeated and the Helmet of Nabu was lost somewhere in the netherverse. It would not be until the early 1960's that Kent Nelson would somehow recover the helmet of Nabu and become Dr. Fate again. In the 1950's Kent Nelson had retired his fate persona and became a physician. It was not until the 1963 that Kent would rejoin the Justice Society of America. As their Justice Society comrades aged, Kent and Inza seemed immortal. The magic fate held over them, virtually stopped their aging process. Inza and Kent also received a small portion of Ian Karkull's power which gave them even more vitality.
When the Justice Society reactivated in the 1960s, Fate was a member - again wearing Nabu's helmet, though how it was recovered has not been revealed. Little is known of Fate's adventures during this period save for the JSA's annual gatherings with the Justice League of America from the parallel world of Earth-One (the JSA being on Earth-Two), and a pair of adventures he shared with fellow JSA member Hourman facing the monstrous Solomon Grundy and the villainous Psycho-Pirate.