Sharra Arryn

Sharra Arryn is an unseen character in Game of Thrones. She is deceased when the events of the series begin. He was the widow of a King of Mountain and Vale and the Queen Regent of Kingdom of Mountain and Vale, ruling in the name of her son Ronnel Arryn, at the time of the War of Conquest.

Background
Queen Sharra Arryn was alongside her son when Visenya Targaryen flew to the Eyrie demanding submission, Ronnel bent the knee to Aegon the Conqueror and surrendered the Kingdom of the Mountain and the Vale in exchange for a ride atop Vhagar.

In the books
In the A Song of Ice and Fire novels, it is unknown to which house Sharra Arryn was born. She was regarded as the most beautiful woman in Westeros.

When Aegon made his intentions known to the Kings of Westeros, Queen Sharra, who was ten years older than Aegon, sent him a portrait of her and a marriage proposal with the condition she made her son his heir. Aegon refused, prompting the Vale to resist the invasion. At the Battle of Gulltown, Visenya Targaryen was defeated, but she managed to burn the Arryn fleet. Rather than join the alliance of the Kingdom of the Reach and the Kingdom of the Rock, Sharra adopted a siege strategy, closing the Bloody Gate and positioning her land armies to massacre the Targaryen army if it tried to force the mountain pass. The result was that the strength of the Vale was not present at the Field of Fire.

Nevertheless, by the time Sharra returned to the Eyrie she found Visenya already there, with King Ronnel sitting on her lap, asking her mother if he could take a ride on Vhagar. The implicit threat of her son being held by Visenya was enough to make Sharra surrender.