Born in 143, King Daeron I Targaryen, known as the Young Dragon or the Boy King, was the eldest son of Aegon III Targaryen and his second wife, Daenaera Velaryon. He acceded to the Iron Throne at the age of fourteen, in the year 157, and became the eighth king of the Targaryen dynasty.
He was then a young, charming and charismatic man, clean-shaven and with long hair. He wore the Valyrian steel crown of Aegon I Targaryen and in battle wore a set of black and gold plates.
Upon the death of his father in 157, Daeron was crowned king of the Seven Crowns even though he was only fourteen years old. His uncle and Hand of the King Viserys preferred not to impose a regency, as the difficult regency of Aegon III was still remembered. Moreover, Daeron seemed to be a capable ruler despite his young age.
Upon his accession to the throne, and at the cost of nearly ten thousand deaths and a year of conflict, the young Daeron made himself famous by conquering Dorne, something no other Targaryen king had achieved before him. Despite the death of the last dragons of House Targaryen a few years earlier, Daeron decided to attack Dorne on three fronts.
He commanded the army attacking through the Bone, which bypassed the Dornish watchtowers using goat paths. Another army, commanded by Lord Lyonel Tyrell, attacked the Prince's Pass and reached the western desert regions.
Finally, the royal fleet commanded by Lord Alyn Velaryon razed Bourg-Cabanes and sailed halfway up the Green-Blood River, cutting the principality in two.
Within a year of the capture of Lancehélion, the prince and the Dornian lords had bent the knee. The following year, the hinterland was pacified and the king secured the submission of the Dornish lords by demanding hostages from the great houses of the principality, who were taken to King's Landing.
However, while the hostages guaranteed the loyalty of these great families, the people of Dorne had never really submitted to the Iron Throne. Lord Tyrell, appointed to lead the principality after the victorious conquest of Dorne, could not prevent the people's revolt from spreading and was murdered while staying in Sandstone.
His death was the spark that rekindled unquenched embers, and the insurrection spread throughout Dorne. In the year 160, the king had to return to the principality and once again he seemed to repeat his feat, but this time at the cost of forty to fifty thousand dead.
The Dornians agreed to talks, but it was only a trap, and they attacked him and his retinue, despite the banner of peace. Daeron perished with some of the sworn brothers of his Kingsguard.
His cousin Prince Aemon Targaryen was wounded and captured. Daeron I died at the age of eighteen without issue, having caused the death of more than fifty thousand men in his futile attempt to conquer Dorne.
During Daeron's military campaigns, the kingdom was administered by his uncle Viserys, who served as Hand of the King for the four years of the Young Dragon's reign.
In addition to the trust that the young Daeron seems to have placed in his uncle by delegating the affairs of the realm to him, he was very much appreciated by his younger sister Daena who idealized him.
Upon the death of the Young Dragon, the throne passed to his younger brother Baelor I, who set about making peace with the Dornian principality and began its peaceful annexation to the kingdom.
