There is an astounding synchronism between, on the one hand, the conflicts between the Kidarite Huns and the Sasanian Empire and the Gupta Empire, and, on the other hand, the campaigns of the Huns under Attila in Europe, leading to their defeat at the Catalaunian Plains in 451. It is almost as if the imperialist empire in the east and west had combined their response to a simultaneous Hunnic threat across Eurasia. In the end, Europe succeeded in repelling the Huns, and their power there quickly vanished, but in the east, both the Sasanian Empire and the Gupta Empire were left much weakened.