In Secrets of Deltora, Doran described two encounters with Forta. The first, on Blood Lily Island, had her telling Doran that her mate was killed by the Ak-Baba a few weeks prior. She was preparing to attack the Ak-Baba and avenge him, but Doran convinced her not to. They spoke again later, where she told Doran that, with her mate dead, Doran was the only one she trusted. This comment moved Doran and helped him realise that even if the dragons did not trust each other, they may still trust him.
Some time after this, Doran found Forta once again and convinced her to hide away and sleep until the king of Deltora woke her. He also made her vow not to enter any other dragon's territory.
Isle of the Dead
Forta is the only one of the seven dragons that make their vow with Doran that does not survive. When Lief, Barda, and Jasmine go through Blood Lily Island - on their way to the Isle of the Dead and the Sister of the West - they are attacked by the Fleshbanes. Lief calls for the Diamond dragon, but she does not come. The group discovers her skeleton covered by Blood Lilies. Jasmine theorizes that the Blood Lilies and Fleshbanes had not been nearly as large in population when she went to sleep, and she had not anticipated sleeping so long that they would become so numerous. The Fleshbanes devoured her in her sleep, and she never woke up. However, the group also discovers an egg clasped in Forta's arms under her head, which hatches upon coming in contact with the Belt of Deltora. Lief suggests that her eggshell was too hard for the Fleshbanes to crack.
Because Forta was dead, Veritas destroys the Sister poisoning her territory in her stead. Doran, kept alive to be the Sister's unwilling guardian, is deeply saddened upon hearing of her death, but is put at rest when Lief shows him her daughter.
The Sister of the South
Forta is mentioned briefly in The Sister of the South. Veritas remains in Diamond territory to teach her daughter, who later helps to destroy the Grey Tide. Lief learned the dragons' true names to each other, including Forta's. Veritas used the opportunity to name Forta's daughter after her mother.
Forta presumably has the same general appearance as all Diamond dragons: silver scales and a pale underbelly that camouflaged her against the sky.
Unlike the other dragons Doran convinced to enter an enchanted sleep, Forta did not survive the centuries waiting for King Lief. Thus, not much is known about her personality. It is however said that she was grieving after the loss of her mate, and that she was building up her strength in order to seek revenge against the Ak-Baba, but Doran convinced her not to.
Like other Diamond dragons, Forta can breathe white fire. Like other dragons, it is assumed that Forta possesses hypnotic eyes and some telepathic abilities. Forta was able to enter an enchanted sleep in order to survive through the centuries, however she was killed in her sleep by fleshbanes.
The word Forta is Spanish and derived from the Latin word Fortis meaning strong. In Deltora the Diamond is the symbol of strength.