I have recently found myself with a project horse, not mine but someone elses-an opportunity to ride for free. He is a 10yo arab/QH who has been out at pasture with two other horses for the past year. Within that year he was not ridden or worked with in any way. So now he will not move without the other horses. He plants his feet and backs up to kicks, rears, bucks, wheels around and tries to bolt back to the herd. Pretty much everything a naughty horse could do. I am generally a gentle rider but I have been very firm with him and haven't changed his behavior much. He will ride decently if another horse is in the field with us. I haven't been at it long, so maybe he just needs time, but I have never had a horse with this problem so any suggestions would be great!