I just started training two four yr old quater crosses this past month. The last few times I worked both of them, they were a little energetic, but otherwise well behaved. Both went around the arena, did several inside turns, and joined up just fine. Neither showed aggresion either, I was very confident in both of them. Yesterday though, when I took the oldest of the two, Luxor, out, he was extremely aggresive. I have never seen a horse act the way he did other than in movies, he wanted to hurt me, really bad. While he was on the lead rope still, he turned to face me and struck, reared and charged me for several minutes. Unfortunately my younger brother was riding my horse who is 33 in the arena with me, so I wasn't able to let him go without putting my brother in danger. I was afraid to punish Luxor in any way as well because it would only drive him towards me and make him more aggresive. If I had been the only one in the arena, I would have just dropped the lead rope and drove him as hard as I could until he was submissive or at least too worn out to do anything, but for my brothers saftey I had to hold on. When my brother finally got out my mom was yelling at me to come out, which meant that I had retreated and he won. I understand she didn't want me to die, which he did charge me several times, twisting his whole body he was bucking so hard, but that means he won. So now, I can't even take him out of his stall without being afraid he'll do something stupid again, so I can't get him safely across the yard to the arena where I will be able to fix the problem. Does anyone have any suggestions?