Born in the year 109, Helaena Targaryen was a princess of House Targaryen, daughter of King Viserys I Targaryen and his second wife, Queen Alicent Hightower. She was married to her brother Aegon. She rode the dragon Songefeu.
Helaena was plump and her beauty was less striking than that of the other Targaryens. She was, however, kind and laughing, and everyone agreed that she would make a good mother.
She adored her dragon Songefeu, and was loved by the people. While there was a deep enmity between her half-sister Rhaenyra and her brothers and mother, it seems that no animosity existed between Rhaenyra and Helaena.
At the age of eleven in the year 120, Helaena was already riding the dragon Songefeu, which had not been ridden since the death of Queen Rhaena Targaryen, the elder sister of King Jaehaerys I.
At the age of thirteen in the year 122, according to Targaryen tradition, she married her older brother, Aegon. The following year, she gave birth to twins, Jaehaerys and Jaehaera. In the year 127, she gave birth to her third child, Maelor Targaryen.
On the first day of 127, the Targaryens held a banquet in King's Landing. After Viserys I Targaryen goes to bed, quarrels break out: Aegon takes offense at the fact that Helaena has been invited to dance by his half-nephew, Jacaerys Velaryon.
On the third day of the third moon of the year 129, Helaena leads her three children to their grandfather, Viserys, in his bedroom. Tired, Viserys finally dismisses them; he dies that same night in his sleep, triggering the war of succession between the Blacks of Queen Rhaenyra Targaryen and the Greens of her half-brother, Aegon II Targaryen.
The day after her father's death, Helaena and her children are having lunch. The Royal Guard comes to find her to know where is her brother-husband, but she answers that they did not sleep together, Aegon having left to indulge himself.
Aegon is crowned a few days later, making Helaena queen consort. Their mother, Queen Alicent Hightower, takes off her own crown to put it on her daughter. She kissed her cheeks, knelt before her and called her "My Queen".
After being crowned in her turn, Rhaenyra proclaims that she will forgive Helaena and her brothers, who were misled by felons. She promises to spare their lives if they come to Peyredragon to bend the knee and ask for her forgiveness.
These terms are rejected by Aegon II, who accuses Rhaenyra of treachery. Helaena and her mother then support Grand Maester Orwyle's proposal to lead a peace embassy to Rhaenyra. They make Aegon II give in, but this mission fails.