Princess Pingyang (Han dynasty)
Princess Pingyang (平陽公主) was the eldest daughter of Emperor Jing of Han and his second empress, Empress Wang Zhi, as well as Emperor Wu's most well-known older sister. Her official title was actually Eldest Princess Yangxin (陽信長公主), but because she married Cao Shi (曹时, also known as Cao Shou 曹寿), the Marquess of Pingyang (平陽侯), she was generally referred to as Princess Pingyang after her husband's enfeoffment.
Even after her marriage, she maintained a close relationship with her brother, Emperor Wu, and he often visited her at her estate. It was at her estate that he met Wei Zifu, who would eventually become his second empress. At the time, Wei Zifu was working as a singer and dancer at the princess' estate. Emperor Wu took a liking to her and brought her back to his palace as a concubine. Wei Zifu's half-brother, Wei Qing, who was working as a horsekeeper at the princess' estate, was sent to work in the palace as well. He would later achieve great military success as a general.
When the Marquess of Pingyang died, Princess Pingyang's advisors suggested that she remarry. Subsequently, she married Wei Qing, who was by then a marquess himself.
Princess Pingyang adopted Cao Shi a son named Cao Xiang (曹襄), who succeeded his father.