Complex sentence: Jomsvikings were forbidden to show fear or to flee in the face of an enemy of equal or inferior strength, though orderly retreat in the face of vastly outnumbering forces appears to have been acceptable.
Split into simpler sentences: Jomsvikings were forbidden to show fear or to flee in the face of an enemy of equal or inferior strength. Orderly retreat in the face of vastly outnumbering forces appears to have been acceptable.