Andreas Johansson wrote:
Another thought about the Tibetans: The rise of the Tibetan Empire is approximately contemporary with the shift in Chinese armies from the cataphracts of the Northern Dynasties to the lighter cavalry of the Tang (Cataphracts to Elite Cavalry in Triumph! terms). This is usually explained as that the lighter types were more useful on the steppe (whereas the cataphracts had been used to smash things in the generally more cramped conditions of the Chinese interior). Why did the Tibetans, who fought primarily the Chinese and steppe types, continue to prefer super-heavies, whether as the or a cavalry type?
I'm not sure those two cultures (Tibet and Northern Dynasty Chinese) were as connected as all that. The warlike Eastern parts of Tibet were more southerly, nearer the Dali, and the Northern Dynasties didn't seem to have much physical contact with Tibet, being buffered by the Tuyuhun and Tangut. And the Tangut continued using heavy armor when they could all the way up through the Iron Sparrowhawks of the Xixia, which is like 12th century or even Mongol conquest.
The question of why the Tibetans and Tangut loved to heavy it up is really interesting, but I wouldn't think they'd switch in response to China switching.
Whenever this sort of question (technological change in warfare) comes up in a wargame forum my first thought is to look for non-wargamer reasons. Partly, I admit, because I'm a contrarian, but also because wargames forums are like the parable of the hammer: if the only tool you have is a hammer, every problem looks like a nail. Which rephrases like this: in a wargame forum, all technological changes in history are interpreted in light of their effectiveness in even-strength battles against historical opponents.
The ultimate example of this is the shift from longbow to gunpowder. It's the posterchild for a wargamer example of post hoc, ergo propter hoc
. Warfare shifted from the longbow to the gun, therefore the gun should be more effective in wargames. Which is totally bulltwinkies -- in range, accuracy, or rate of fire a trained longbowman outperformed a musket user (much less matchlock, flintlock, or earlier handgonne) until the best weapons of the US Civil War. The longbow fell out of use for logistics reasons -- it took many years of continuous training to produce a single longbowman. And the 15th century rise of the wool trade in England converted fields used for yeomanry into pastures for sheep. As soon as England wasn't in a state of constant civil war, their longbow use evaporated and couldn't recover -- just like France never managed to develop any effective longbowmen in the 15th century, in spite of constant examples of the effectiveness of that tool of war. Logistics, not warfare effectiveness.
So whenever technological change happens within a culture's warfare tools, the first place I look is logistics -- cost, in one sense or another.