Empire across the Himalayas

Question

I was bouncing ideas off the wall about empires that could've plausibly existed in Asia if certain things went differently, and I stumbled across the very physical barrier of the Himalayas.

So my question is this: how great a physical obstacle is the Himalayas, exactly? Is it totally impossible for a political entity in say, Tibet, to rise and unite both East and South Asia in a single Empire? I'm aware that this is possible to a certain degree: the Tibetan Empire that emerged in the 7th century managed this to a certain extent. It was a big thorn in the Tang Dynasty's side, and some maps show its suzerainty over territories as far south as Bengal in the Indian subcontinent. However, that was as far as it got, while what I'm envisioning is more like Qing China and Mughal India combined, territorially speaking. Is that totally implausible due to the Himalayas?

(Later edit: removed a more speculative part of the question)

Answer 1

I think the main problem you've set yourself here is having any empire control all the territory of east and south Asia, regardless of where its core territory is situated. While China and India may look like territorially stable countries today, historically these regions were constantly splintering apart, then being united under a new strong government, then splitting apart again, over and over and over.

One possibility to get to something close to what you're after is to imagine Genghis Khan was born, (and the conditions that made him were present) in Tibet instead of Mongolia. This would be a flash-in-the-pan kind of empire, one built very quickly from the martial prowess of a single talented leader, taking advantage of weak and decaying governments to the south and east. But empires that rise quickly tend to fall quickly, and once your Tibetan Khan dies, there's every chance the lands they conquered will quickly reassert their independence. At best, this Himalayan Empire will leave successor states behind, but even these will quickly "go native" - case in point, compare the Mughal Empire in India and the Yuan Dynasty in China, both direct descendants of the Mongol hordes, but not particularly very similar to one another in any other ways.

Answer 2

Yes, Mountain Empires are Possible

While mountain ranges, especially very expansive and high altitude ranges such as the Himalayas are considerable barriers for human movement and settlement history shows that they are not an insurmountable barrier.

As mentioned in your question, the Tibetan Empire was a Himalayan Empire that had considerable geopolitical power at its height, and was mostly constrained by its more powerful eastern neighbor than any failing of geography. Pastoral nomadism is a very adaptable life way for empire building, as demonstrated repeatedly by the steppe tribes of Central Asia. Pastoral nomadism negates many of the problems with running a montane empire, and would be conducive to force projection over a large area. The biggest problem for such an empire is projecting into terrains where the nomads cannot function (see the Yuan Dynasty’s failed invasions of Vietnam and Java for two South East Asian examples)

Another Mountain Empire to consider is the Inkan Empire. The Inka controlled an empire stretching for over two thousand miles of the Andes mountains, and also extended into parts of the Amazon basin and the Atacama desert. The Inka domesticated crops that were highly tolerant of the severe climate, such as the potato.

Answer 3

Most of the successful nations and empires in history were founded on lowland river deltas. What are the reasons for this?

The primary answer aside from the obviously challenging matter of large scale food production, sanitation, and resultant ease of population growth, is that economies and militaries rely on ease of transport and access.

Mountains are notoriously difficult to mould to human needs. A group might take many years to carve a single, narrow mountain pass to allow treacherous passage in single-file. To carve that wide enough to allow an army to pass safely - never mind all the mishaps that can happen during construction due to natural seams and fault-lines in the stone - requires modern technology. Never mind robust bridges across steep gorges etc. None of this was easily possible until the 19th c.

There is a reason that it is difficult for most of us to think of many mountain empires in history: there really weren't any (that lasted long in the face of competition from more conveniently placed kingdoms and empires).

Mountains are easy to defend from, it's true. But lacking a large population and the ability to make them mobile in short order, kind of limits your options in terms of taking over the rest of the world. This could be mitigated by moving your capital out of the mountains into a captured lowland city, but then... well... you're no longer primarily based in a mountainous region, are you? Remember that administration in former centuries relied very much on physical proximity, so again, having a mountain capital severely limits such administration.

It is conceivable in a fantasy world, that dwarves or trolls with great strength, great stoneworking skill, magical picks and countless existing tunnels (such as the network built by the Viet Cong, but in stone) might be able to forge an empire with its administrative centre in a mountain range.