Visenya and her sister and brother were both born on the island-fortress of Dragonstone. The Targaryens had held the island for two hundred years before the Doom of Valyria. In the century after the Doom, the "Bleeding Years", the Targaryens tried to expand their holdings. However, Aegon had been torn between unifying the continent of Westeros or conquering the Free Cities, which had been experiencing bloody strife in the aftermath of Valyria's fall. Aegon, and his sisters opted for the invasion of Westeros, instead of conquering the Free Cities of Essos. At the very beginning of 1 AL, Aegon I Targaryen and his two sister-wives Rhaenys Targaryen, and Visenya Targaryen, landed on the eastern coast of Westeros, with a large army of soldiers, and the Targaryen's three dragons. With very limited manpower, the Targaryens knew that their full-grown dragons would be their ultimate weapon.
Conquest of Westeros
After the death of Harren Hoare at Harrenhal, Visenya was sent by Aegon to demand the submission of the lords of Crackclaw Point. The lords of Crackclaw saw their eminent defeat, so they laid their swords at her feet. Visenya took them as her own men and they would swear fealty to none but Visenya. After conquering the Riverlands, the Targaryens quickly gained alarming success by conquering the neighboring kingdoms. King Loren Lannister of the Rock, and King Mern IX Gardener of the Reach, formed an alliance and assembled their arimes to face the Targaryen invaders. Visenya, Rhaenys and her brother, deployed all three of their dragons at once. Their combined dragons, covered the entire battlefield in fire, buring four thousand men and King Mern himself. The battle-site became known has the Field of Fire. King Loren then swore fealty to Aegon and was allowed to remain Lord of Casterly Rock. King Mern was dead, so ownership of the Reach went to Harlen Tyrell, who was Merns steward. The Targaryen accepted their oaths.
After the invasion of The Reach, the Targaryens then control over the six of the seven Kingdoms of Westeros. Visenya than married her brother Aegon I Targaryen, along with her younger sister Rhaenys Targaryen. The three Targaryens ruled with great wisdom and peace, Visenya later gave birth to her only son Maegor the Cruel.
Reign of Aenys I and Maegor I
After her brother's death and ascension of her nephew Aenys, Visenya seemed to prefer to dwell at Dragonstone alongside Vhagar. The actions of the Faith Militant against the crown angered her and urged her nephew to take decisive action, something Aenys seemed reluctant to do. When Aenys died of a sudden illness (although many believe she poisoned him), she flew to Pentos and brought her son Maegor from exile. When Maegor took the throne, he put Queen Dowager Alyssa and her children Jaehaerys and Alysanne under her custody at Dragonstone while he warred against the Faith. She passed away in 44AC, this allowed Alyssa and her children to leave Dragonstone.
After Aegon's death, Visenya's son Maegor I Targaryen and nephew Aenys I Targaryen ruled Westeros somewhat together. Maegor was considered to be too violent and cruel. Her nephew Aenys was too weak and left the duty of running the military to his half-brother while he was tasked with the everyday runnings of the kingdom. This was widely accepted because of the cruel nature of Maegor. Visenya's line, unlike her sister Rhaenys' ended with the death of her only son Maegor, who was presumably murdered while on the Iron Throne.
Character and Appearance
Visenya shared the same traditional Valyrian looks as her sister and brother. Her silver-gold hair was braided and bound in rings, she also had the unique lilac eyes of the Targaryens. She dressed in a warrior-like attire and carried the Valyrian sword Dark Sister. She was stern, sensual, and passionate, as well as intensely wilful. Towards the end of her life she became very thin and haggard, unable to wield Dark Sister as a result, but just about to mount Vhagar if she wanted to. She had a monstrous temper.
She was also more of a temptress with a dark, unforgiving side to her. Visenya and her sister would often compete for Aegon's attention, but each in their own way. Visenya was well known for being the polar opposite of Rhaenys: It cannot be a coincidence that she owned a sword called Dark Sister. Visenya's relationship with her younger brother, while already strained, became even more distant after Rhaenys' death. Rumours webbed King's Landing that Aegon left Visenya to the construction of the Red Keep so that he wouldn't have to endure her presence. However, while Rhaenys was known to entertain some men in her bedchamber, Visenya's fidelity to Aegon was not so easily denied.
Visenya was extremely blunt: when they were attacked in the streets, Visenya berated Aegon for his ineffectual guards, before going so far as to scar his cheek with her sword to prove her point. This led to the creation of the Kingsguard. She went on to advocate the laws and vows of the Kingsguard, desiring them to be the greatest, most loyal and efficient knights in all the realm.
Especially later in her life, Visenya proved to be uncompromising, cruel and unapologetic about her opinions - she remained completely critical of King Aenys' actions during his time as king, believing him to be weak despite having loved his mother. She openly defied Aenys by officiating the unlawful marriage between her son and Alys Harroway, chastised him for not returning fire on the Faith Militant when they defied him, and by the end of her life she had very few admirers at court, because so many were terrified of her. She advocated violence throughout the reign of Aenys and later Maegor, who proved to be far more dangerous than her.