Space Knights of Camelon (S04E03)

As Superman defends a prehistoric world from an incoming meteor, he is struck by the meteor's nuclear core, causing him to crash onto the medieval planet of Camelon, where he loses his memory. A group of rebels, led by Logan, takes advantage of the situation, enlisting him as their black knight in their scheme to dethrone King Arthur VII. Meanwhile, the Super Friends must race against time to restore Superman's memory and thwart the rebels’ plans.