Otto Hightower

"Ser Otto Hightower, the Hand of the King and father to Queen Alicent, demanded that the succession be settled immediately."

- - Viserys Targaryen Otto Hightower is an unseen character in Game of Thrones. He is not expected to appear in the series, being long dead by the time it starts. He was the Hand of the King of both Viserys I Targaryen and Aegon II Targaryen.

Biography
Otto served King Viserys I Targaryen, as his Hand, from 120 AL until his death. Upon hearing this, his daughter Queen Alicent Hightower, Viserys' wife, ordered that the servant who first saw him dead be put in the Black Cells. Otto then summoned a Small Council meeting, and he demanded that Aegon II Targaryen would be King. However, the small council members were confused, as they had been demanded by Viserys that they must swear fealty to his eldest child Rhaenyra Targaryen. The Master of Coin, Lyman Beesbury, declared this as treason, only to have his throat cut open by Ser Criston Cole, who had previously pointed out that a son comes before a daughter, despite the sucession that the dead king had refused to change. This ended the debate at dawn.

With his eldest son, Jaehaerys Targaryen, dead, Aegon was currently losing in the Targaryen civil war known as the Dance of the Dragons. His nephews had also recruited House Stark of Winterfell, House Arryn of The Eyrie and the other houses of The Vale of Arryn for their mother Rhaenyra. Furious, Aegon dismissed his Otto, and appointed Lord Commander Criston Cole as his new Hand.

In the books
Ser Otto was famous for his knowledge. For this ability, he was named Hand of the King. He is now a warning to future Hands that knowledge is not everything. He served as Hand of the King under Jaehaerys I, Viserys I, and Aegon II Targaryen, but was not Hand continuously.

Otto first served as Hand after the death of Jaehaerys's Hand and son, Prince Baelon Targaryen. Jaehaerys was devastated by the death of his son and loss of his beloved wife earlier, becoming grief stricken, and with his health failing he became bedridden. Otto effectively ruled the kingdom as Hand in the final two years of Jaehaerys's reign while his daughter Alicent Hightower nursed the ailing king.

Otto continued as Hand to Jaehaerys's successor, Viserys I Targaryen. He was father to Viserys's second wife, Queen Alicent. In 109 AC, Otto was removed as Hand for hounding Viserys to declare Alicent's sons the heirs to the Iron Throne instead of Princess Rhaenyra Targaryen. Having no place at court anymore, Ser Otto returned to Oldtown. A "queen's party", known as the greens, a group of powerful lords who were friends with Queen Alicent, remained, who supported the rights of Alicent's sons.

In 120 AC, Otto returned as Hand after Lord Lyonel Strong died. When Viserys died in 129 AC, Otto played a crucial role in crowning his eldest grandson as King Aegon II in defiance of the last will of Viserys I, which specified Rhaenyra as the successor. This defiance precipitated the civil war known as the Dance of the Dragons.

The Dance of the Dragons
The opposing faction, the blacks, included the battle-tested Prince Daemon Targaryen, who, in the course of his pre-war adventures, had made many foes. Ser Otto had been amongst the first of these. He reached out to other enemies of the prince, the Kingdom of the Three Daughters, as allies. They were crucial in breaking the Velaryon blockade in the Battle in the Gullet.

Aegon II, however, perceived Otto's diplomacy as slothful at a time when Prince Daemon had captured Harrenhal and many houses had declared for the blacks. This led to his replacement as Hand by Ser Criston Cole, the Lord Commander of the Kingsguard, despite the pleading of Ser Otto's daughter (and Aegon's mother), Queen Alicent Hightower. It was only after his dismissal that his efforts bore fruit.

Otto was the first to be executed as a traitor by Rhaenyra Targaryen when she took King's Landing in 130 AC, just as he had predicted.