Daeron II Targaryen, also called Daeron the Good, is an unseen character in Game of Thrones. He is not expected to appear in the series, being long dead by the time it begins.
Daeron was the second King of his name to sit on the Iron Throne and the twelfth king of the Targaryen dynasty to rule the Seven Kingdoms. He was an ancestor of Viserys and Daenerys Targaryen. He was formally styled Daeron of House Targaryen, the Second of His Name, King of the Andals and the First Men, Lord of the Seven Kingdoms and Protector of the Realm.
Daeron was the son of King Aegon IV Targaryen and Queen Naerys Targaryen, born on the year 159 since Aegon's Landing. He had a sister, Princess Daenerys. He also had a half-brother, Daemon Blackfyre, born of the affair between his father and Queen Daena Targaryen, the sister-wife of Baelor I Targaryen.
During his reign, his half-brother Daemon rebelled against his rule to claim the Iron Throne for himself. Daeron perished during the Great Spring Sickness. He was succeeded by his son Aerys.
Daeron II, along with siblings and progenie, is mentioned in the House Targaryen's entry of the book The Lineage and Histories of the Great Houses of the Seven Kingdoms. He's described as purple blue of eyes, silver of hair and round of shoulders.
In the books
In the A Song of Ice and Fire novels, Daeron II was a dignified man. He had a kind thoughtful face. He was round-shouldered, with thin legs and a small pot belly. His face has a certain quiet strength, though, and his eyes are clear and full of resolve. He wore his father's elaborate dragon Crown. On his coinage, he was depicted as clean-shaven. He was not a warrior by any means, but a cultured, scholarly man who kept company with maesters and other learned men.
After the failed Conquest of Dorne, King Baelor the Blessed arranged the marriage of his Prince Daeron to Princess Myriah Martell of Dorne as part of a dual marriage pact between the two kingdoms, thus bringing Dorne into the Seven Kingdoms. He also officiated at the wedding ceremony. Princess Myriah brought many of her native manners and customs with her, and many noble Dornishmen and women flocked to his court, all serving to give life in the Red Keep a foreign flavor, and alienating many of Daeron's nobles and courtiers. In 170AL they had their first son, whom they named Baelor in Baelor the Blessed's honor. Daeron founded a new castle at Summerhall, in the Dornish Marches, roughly where Dorne, the Reach, and the Stormlands come together.
Late in Aegon IV's reign, it was whispered that his father had come to believe that Daeron was not his son, but the product of an illegitimate union between his wife Naerys and their brother, Aemon, and was planning to disinherit Daeron in favour of Daemon Blackfyre. Daeron ascended to the throne, however, following Aegon IV suddenly illness and death. Nevertheless, several military-minded lords gathered around Daemon and supported his claim to the Iron Throne, causing the First Blackfyre Rebellion.
- Daeron II Targaryen at A Wiki of Ice and Fire (spoilers from the books)