Third child and eldest daughter of King Aegon III and Queen Daenaera Velaryon, born in 145 AC, Daena was wild almost from birth, a Targaryen to the bone: strong, beautiful, and willful, an expert horsewoman, hunter, and archer who worshiped her father and idolized her brother Daeron. In 160 AC, at fifteen, she was wed to her brother Baelor, but the pious king refused to consummate the marriage; she took to dressing all in white and swore to wear nothing else until she was properly bedded, to no avail.
When Baelor took the Iron Throne in 161 AC he had the unconsummated marriage dissolved and shut Daena and her sisters in the apartments that became the Maidenvault, where she won the name the Defiant by escaping thrice in the guise of a servant or a smallfolk girl. Late in 170 AC she bore a bastard son she named Daemon, after her grandfather, and refused to name the father, later revealed to be her cousin Prince Aegon, afterward King Aegon IV; the boy would be legitimised as Daemon Blackfyre and one day raise the first Blackfyre Rebellion. After Baelor's death some among the smallfolk and lords held that the throne should pass to Daena as Aegon III's eldest surviving child, but the precedents of the Great Council of 101 AC and the memory of Rhaenyra set her claim aside in favor of her uncle Viserys II. She is last attested in 172 AC.