In the Mahabharata, Surya—the solar deity—is the father of Karna. Karna is born when Kunti uses a mantra granted by the sage Durvasa to summon a deity and conceives a son by the Sun god.
Karna’s divine parentage explains his extraordinary birthmarks: he is born wearing natural golden armor and earrings, often called kavacha and kundala. Fearing social disgrace because she is unmarried, Kunti places the infant in a basket and sets him afloat. The charioteer Adhiratha and his wife Radha find and raise him, so Karna is also known as Radheya, “son of Radha.”
A common mix-up is confusing Karna’s divine father with the deity connected to another major warrior. Indra, king of the gods, is the father of Arjuna, Karna’s rival and half-brother through Kunti. Surya’s identity also shapes Karna’s later story: he warns Karna that Indra intends to take away his armor and earrings, but Karna gives them away in charity, making himself vulnerable before the war.