Other than when Nabu himself has taken on the role of Doctor Fate, the Helmet of Fate is the link between those acting in the role and Nabu himself. The most famous Doctor Fate, Kent Nelson, had a certain amount of abilities taught to him by Nabu including flight, super strength and limited invulnerability, but only gained full power when wearing the helmet. Because of this numerous others have sought the helmet for themselves. Due to the strong will of Nabu, the helmet is also known to overwhelm the mentality of its user. Because of this for a time Nelson wore a half mask based on the appearance of this mask, but thus lost most of his magical powers while fighting crime.
After the death of Nabu at the hand of The Spectre, the helmet is entrusted to Detective Chimp to find the next Doctor Fate. Deciding to leave it up to fate, he instructed Captain Marvel to hurl it into space. On its long journey the helmet comes across Black Alice, Sargon the Sorcerer, Ibis the Invincible, Detective Chimp again and Zauriel until finally coming upon Kent V. Nelson, the grandnephew of Kent Nelson. Kent wears a half helmet and since Nabu no longer lives inside it he possesses all the abilities of his predecessors without having the vie with the influence of a powerful being inside his head.
In the world of Flashpoint, the Helmet of fate is still a much sought out artifact and still possessing formidable magical powers. So much in fact that the Amazons dispatches a search party to recover it from Kent Nelson, a fortune teller with a traveling circus, and kill anyone in their way. During the attack on the circus, Kent is killed and the Helmet is passed to the recently orphaned Dick Grayson who takes up the mantle of Dr. Fate at the conclusion.