Jellal and Erza have been Friends for a long time. They first met in the Tower of Heaven, back when it was being constructed. During this time, Jellal gave Erza her last name. Jellal cared deeply for her, to the point of changing places with her when she was about to admit to a crime that she didn't commit. However, when Erza went to save him from the guards who captured him, he, having been brainwashed already, attacked her and exiled her from the Tower of Heaven, making everyone think she betrayed them.