Just a quick question. Other than firearms, what are some good examples of advanced weaponry for an early-to-middle medieval setting? In my WIP one of the protagonists is trying to track down who is supplying a barbarian tribe with advanced weapons that are decimating his lands. So I'm not sure what type of weapons would be unusual or too advanced for a barbarian tribe to have. Thanks in advance!
Crossbows, imagine a ballista like device pulled by oxcart with a giant hand crank that draws back 20-30 oversize crossbows, siege towers, cannons.... Horses and chariots could be a big deal - imagine barbarians being sold the metal components for the most modern war chariot. Someone could sell them 2 or 3 thousand horses that were meant for the legion - Arabic warhorses from across the ocean bigger than any local breed.
The barbarians could have been supplied a trebuchet on wheels, though it may be tricky for them to operate at first.
If you go to Wikipedia and look up "List of Medieval Weapons" you can find out which ones were cutting edge at the time your story is set.
The biggest hurdle for barbarian tribes, especially nomadic ones is the production of high quality steel. The ore, the furnaces, large scale forging, are fairly immobile and require advanced (for the time) technology.
High quality steel. Especially armor amongst those barbarian warriors who wouldn't normally be able to afford it.
Typically people think crossbows, but long bows were a significant improvement over traditional bows. The arrows could move longer distances, and were more lethal than traditional bows. In fact, for a number of years the long bow swung the tides of battle and were even feared more than some mounted soldiers.
Honestly it wouldn't even take weapons to turn the tide for a nomadic tribe. Teaching them simple tactics; how to maintain an army, formations, guerrilla warfare techniques, combat training, and large numbers are enough if there isn't any stout resistance around. Think Spartacus.
I think Greek fire might be a good fit, it was used around 600 AD by the Byzantines and was such a closely guarded secret the recipe was eventually lost. The closest modern equivalent is napalm, It was a liquid petroleum based weapon which stuck to anything and burned even on water, it could only be put out by smothering it and produced toxic fumes. Traditionally the Byzantines used it in naval warfare with a pump but it was also allegedly used as a grenade.
