The origin of the word havoc

I came across the passage below in a web-dictionary as follows:

If we trace havoc way back, we arrive at a crossroads. Some people believe that the word comes from the Old French havot, meaning “plundering, devastation,” while others argue that it was passed down to us from the Latin habere, meaning “to have, possess.” Either way you look at it, the meaning remains the same: widespread disorder or destruction.

It says havoc's meaning of “plundering, devastation,” can be extracted from the Latin habere, meaning “to have, possess.”

But how does the meaning, “plundering, devastation” come out of “to have, possess”?

Wish for your replies.
From the Online Etymology Dictionary (http://www.etymonline.com/index.php?term=havoc ):

"early 15c., from the expression cry havoc "give the signal to pillage" (Anglo-French crier havok, late 14c.). Havok, the signal to soldiers to seize plunder, is from Old French havot "pillaging, looting" (in crier havot), which is related to haver "to seize, grasp," hef "hook," probably from a Germanic source (see hawk (n.)), or from Latin habere "to have, possess." General sense of "devastation" first recorded late 15c."

So, the connection seems to be "have, possess" -> "seize, grasp" -> "plunder" -> "devastation, disorder, destruction"
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There is a straightforward and simple explanation for this. It is from the Middle English word, havok, which in turn derived from Anglo-French, the French that was spoken by Norman conquerers. It was originally from the Old French word, havot, meaning plunder. That is, the Normal conquerers spoke French, but their French was subtly, and irresistibly, influenced by the Anglo-Saxon language of their subjects. So their Old French word, havot, over time, became "Anglicized" to havok, which differs in spelling only, from our modern havoc.
AnonymousThere is a straightforward and simple explanation for this.
I don't see how your reply addresses the question that was asked.
It actually comes from the Anglo-Saxon for hawk, "hafoce".
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"It's ours!" or ""We've got it!"

Yes, the basic idea is that I took your stuff by violence. Now I have it and you don't!