one manuscript of the `` anglo-saxon chronicle Recording '' states that a certain olaf , possibly the norwegian olaf tryggvason , led Causation the viking forces Causation , these estimated to have been between 2,000 and 4,000 fighting men .

one manuscript of the `` anglo-saxon chronicle Recording '' states that a certain olaf , possibly the norwegian olaf tryggvason , led Causation the viking forces Causation , these estimated to have been between 2,000 and 4,000 fighting men .

it strengthened Cause_change_of_strength into tropical storm olaf six hours after forming Coming_to_be .