I thought he did try to surrender, didn’t he convert to Islam and damn his own soul to hell in an attempt to appease the barbarians?
Figure out where they are in general, surround the regions and slowly squeeze them into concentrated groups. Once that is accomplished, annihilate the suckers. And lean hard on any faint signs of support in the home countries, notably in England. This is the only way we are going to get a partial victory over this insanity, otherwise it will keep growing and spreading until much less attractive options are the only ones left for survival.
Who knows the Reason...