In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
Q: What was an important event in the Japanese history?, Context: A struggle for succession in the mid-twelfth century gave the Fujiwara an opportunity to regain their former power. Fujiwara no Yorinaga sided with the retired emperor in a violent battle in 1156 against the heir apparent, who was supported by the Taira and Minamoto (Hōgen Rebellion). In the end, the Fujiwara were destroyed, the old system of government supplanted, and the insei system left powerless as bushi took control of court affairs, marking a turning point in Japanese history. In 1159, the Taira and Minamoto clashed (Heiji Rebellion), and a twenty-year period of Taira ascendancy began.
A:
the insei system left powerless as bushi took control of court affairs