But no civs. particularly those of antiquity exists without military institutions. Didn't Harappans known to tame elephants for combat purpose?
Short answer: No, not yet.
There is indirect evidence that elephants may have been tamed for use as draft animals as early as 2000 BCE, but it's hotly debated whether they were used in the Indus Valley. The earliest mention of War Elephants is in the
Ramayana and
Mahabharata, Hindu epics from about 5th - 4th centuries BCE, describing events from as far back as 1100 BCE - still almost a 1000 years after the Indus Valley civilization declined.
There are lots of clay/terracotta figurines found in the archeological sites of the Harappans: they depict largely oxen and chickens and more rarely, horses. In the very late (declining) Harappan period there is a model of a chariot drawn by 2 horses, but by this time the earliest Vedic (Indo-European) migrants are appearing, so this might have been a 'borrowed' technology - since we cannot read a word of the Indus script, we just don't know.
Significantly though, there are no models or figurines of elephants.
The most certain aspects of the Indus Valley Civilization are:
1. Extensive water management technology, both widespread irrigation systems and 'plumbing' even into individual houses with primitive toilets, wash basins, and running water, city drainage and sewer systems.
2. Widespread trade on both land and sea - no models of boats found, so what kind is anybody's guess, but constructed harbors on coastal sites and canals that are too big for irrigation, so presume some kind of river boat traffic. Trade goods found from Mesopotamia, Central Asia, central India, Iran and the Persian Gulf. They had standardized weights and measures, and Trade and manufacturing goods for trade seems to have occupied the majority of the city populations.
3. NO direct evidence of armies or major military establishments - cities are walled, but no hoards of stored weapons as are found in Mesopotamia and Greece, no statues, figurines, or wall frescos of massed warriors or soldiers. This doesn't mean they were unarmed, but it implies that any military they did have was not very important to them.
4. It was HUGE. Over 1000 sites found from the borders of Afghanistan to the modern Pakistan/Indian coast, including cities of 30 - 60,000 estimated population and pretty much uniform cultural artifacts rom one end to the other. Whether that means it was all a single "Empire" or a web of city states is still debated. One indicator, though, is that nothing resembling a Central Palace or governing complex has been found in even the largest of the cities, which seems to rule against a central government.
So, the problem with a Harappan military is not that it didn't exist, but that at the moment we don't have any idea what it looked like or what, if any, specific type of 'particular' (Unique or Emblematic) unit they may have fielded.
That's what led me to (tentatively) conclude that
Humankind's Harappan Courier might be a 'semi-military' unit to enhance contact and trade, which would tie in with one of the salient features we can certainly ascribe to the Harappan Civilization.
