Of Gold and Glory

House Saerpentis is the third great Valyrian House that survived the Doom. They conquered the kingdom of the Golden Islands by allying with local ruling families.
Serinna Saerpentis is the princess and heir to the kingdom. However, her father sends her to Westeros where she is chosen to become the wife of Viserys Targaryen, for her great beauty and Valyrian blood. Serinna is a true ruler and a strategist so her removal from the inheritence line is not something that pleases her. She does everything in her power to protect the position of her daughter-in-law and friend, Rhaenyra Targaryen. When the King's mistress gives birth to two bastards children, Serinna gets her marriage annuled and goes back to the Golden Islands.
Years later, when she dies from illness, her daughter Lyra is also send to Westeros to be place under Rhaenyra's care. When Rhaegar Targaryen, son of Alicent Hightower usurpates the throne, the children of Serinna Saerpentis are caught up in the middle of the Dance of Dragons.