Yidu did not have a long stint on the popular series but she still made an impact all the same. Yidu was introduced in season 4. She was one of the slaves who was captured in Frankia and brought back to Kattegat. Yidu was the only Asian among the slaves, which
garnered the attention of Aslaug, who decides to buys her. It is the same foreign appearance of Yidu that catches the attention and attraction of Ragnar, as he had never seen someone like her before. Yidu provided the series with something different and added another layer to Ragnar.
Yidu eventually reveals to Ragnar that she is the illegitimate daughter of the emperor of China. She also provides Ragnar with a substance to cope with pain that he becomes heavily addicted to. Together, they share this secret and eventually become lovers. Yidu meets her end at the hands of Ragnar, however, after she refuses to give him the substance and threatens to reveal his secret addiction.