I have often heard that the ancient Assyrians were very brutal and committed many acts of violence when dealing with other peoples, much more so than many other empires. They seem to be remembered for their brutality and their methods when doing war and diplomacy.
How much of this is true? Where the Assyrians truly anymore brutal than other empires? Or is it all just some sort of bias against them?
To am extent: the takes if their brutality is drawn directly from the horse's mouth, so to speak. Assyrian narrative inscriptions frequently give quite a bit of gruesome detail to their treatment of rebels and other traitors. Flaying, public dismemberment and other such executions are featured in their gory splendor. Whether this was unusual for the time is another debate, one that isn't settled among relevant specialists, but the stories if their brutality have direct documentation rather than being a set of myths accruing later.
Now, that being said it is possible to problematize that. Assyrian palaces were laid out as a set of increasingly interior zones: a traveler would go from one courtyard to the next, each one less public than the last. The gory scenes of brutality are on the exterior zones, while the interior has images of hunting and royal leisure. So these image sets can be seen as a way of sending a message to envoys: those on the outside get the stick, but if you are peaceful with us and join us in friendship, see what pleasures await!
Incidentally, if you would like a good intro to Mesopotamia with lots of maps, I would recommend Michael Roaf's Cultural Atlas of Mesopotamia.