The Nine Mistress of Aegon IV
Though Aegon IV the Unworthy had countless lovers, he claimed to have loved only nine of them, and that his wife, Naerys Targaryen, was not among them:
Falena Stokeworth. She had been a candidate for the second wife of Aegon III, Aegon's uncle, but broke her leg the day before the presentation. She became Aegon's first lover, who "made him a man" when he was fourteen. The affair lasted three years, and when discovered by Aegon's father Viserys, Falena was married to Lucas Lothston, later made Lord of Harrenhal, but is said that Aegon to have continued to visit her for several years.
Megette. A blacksmith's wife whom Aegon bought for seven gold pieces and the threat of his guards. They had a four-year affair during its she bore Aegon four daughters: Alysanne, Lily, Willow, and Rosey. When Viserys found out, he sent Megette back to her husband, who beat her to death within a year, and gave their four daughters to the Faith.
Cassella Vaith. Cassella was the daughter of Lord Vaith and came to court as a hostage during Daeron I's Conquest of Dorne. She became Aegon's mistress but he soon grew tired of her and had no problem handing her over when, upon Daeron's death, the hostages were supposed to be killed (Baelor I decided to send them home instead). Cassella never married and lived in the belief that she was Aegon's one true love and that he would soon take her back.
Bellegere Otherys. A Braavosian merchantess and piratess, she met Aegon when Baelor sent him to Braavos to give Naerys some respite from his near-death experience after a stillbirth. They had a ten-year affair and three children, Bellenora, Narha, and Balerion, though many claimed that Bellegere had lovers everywhere and that the children could have been anyone's.
Barba Bracken. She had been a lady-in-waiting of the Maidenvault at the end of Baelor's reign, and met Aegon when the princesses were freed. She was his mistress when he rise as king and bore him a son, Aegor (Bittersteel), two weeks before Queen Naerys give birth the princess Daenerys and a stillbirth son, after a painfull labour that brought her to the brink of death. At that point Barba and his father, the Hand, began to speak openly of marriage, and this led to their downfall: Aemon and Daeron, Naerys's brother and son, forced Aegon to send them away.
Melissa Blackwood. Considered the most gentle, kindhearted and modest of the Aegon's mistresses, Melissa, who bore him three children, Mya, Gwenys, and Brynden (Bloodraven), was well loved by court and even managed to become friends with Naerys, Daeron, and Aemon. When, after five years, she realized she was losing the king's favor, she retired gracefully, and the nice memory she left behind at court facilitated the rise of her son Brynden.
Bethany Bracken. Sister of Barba, she was trained with the specific purpose of replacing Melissa and avenging her sister. However, she was caught cheating on the king and executed with her father and her lover.
Jeyne Lothson. Daughter of Falena Stokeworth and her husband, many believed that she was actually Aegon's own daughter, and this led to all sorts of rumors spreading, including that Aegon was having threesome with both mother and daughter at the same time.
Serenei of Lys. Aegon's last mistress, she was considered the most beautiful of them, but the coldest, despite Aegon's calling her "Sweet Serenei", and was accused of being a witch. Last descendant of an ancient and noble but poor Valyrian Lyseni family, she died given the king his last known child, a daughter named Shiera Seastar.
Honorable mention goes to Daena and Elaena Targaryen, who were sisters and Aegon's cousins. Daena had by Aegon a natural son, Daemon Blackfyre, while, although not proven, it is likely that he was also the father of Viserys Plumm, Elaena's son.