A Thanagarian was a member of the native race of the planet Thanagar. They were recognizable by a pair of large, feathered, flight-capable wings on their backs, but were otherwise indistinguishable from humans.
The people of Thanagar once worshiped a pantheon of extradimensional entities known as The Great Old Ones. At that time, Thanagar was a harsh world and theirs was a primitive and savage culture; in return for offerings made to him, the Old Ones' leader, Icthultu, gave them agriculture, mathematics, and philosophy — the foundations of their entire culture. As they matured, however, the Thanagarians stopped worshiping them — modern-day Thanagarians bow down to no higher power. Their knowledge of the Great Old Ones was used in the creation of their personal weaponry. For this reason, their Nth metal weapons — such as Hawkgirl's mace and Hro Talak's battle-axe for example — have mystical properties and can work against Green Lantern's power ring or Superman's invulnerability.
In 6600 B.C., two Thanagarian law officers were stranded on Earth, and were worshiped as gods. They used their positions to unite the surrounding lands in hopes of bringing peace and prosperity to Earth.
Later, an emissary of Thanagar — the army commander Hro Talak — declared to Earth that for generations, Thanagarians have been locked in war with their enemies known as the Gordanians. They said that they will construct a shield generator that would protect the entire planet. Unfortunately, their real intention was to destroy Earth to create a hyperspace bypasses to go right to the Gordanian homeworld. The Justice League stopped them and the Thanagarians left the planet. When they returned to Thanagar, the planet was already decimated. Hro Talak told his remaining crew to abandon ship while he ran a kamikaze attack on the Gordanian mothership.
The final fate of Thanagar under Gordanian rule remains unknown, but there was a resistance movement fighting against the Gordanians. Paran Dul, Kragger and a few Thanagarians later left the resistance to pursue Shayera Hol for betraying them.
Thanagarians were able to have children with humans.