Got a Real-World Weapon, Armour or Tactics Question? Mk. XXVIII

[AdAstra]

There have been battles over several days throughout history. In the pre gunpowder era they were more common in Asia than in Europe.

Some factors that make a multiple day battle more likely include.
- Very large armies.
- Both sides having favorable defensive ground.
- A reliance on missile weapons over melee.
- Evenly matched opponents (after taking into account technology differences and terrain advantages).

The two big factors that made 20th century warfare feature multiple day battles as standard
- dispersed formations due to machine guns, smokeless rifles and efficient artillery.
- the ability to command further, through field telegraphs, telephones and wireless. This allows further dispersion of troops and the co-ordination of reserves.

I wonder if the existence of more cohesive "frontlines" and supply chains might have also contributed. Retreating can become a lot less strategically sound due to potentially opening up the flanks of the units to your sides, and with continuous delivery of supplies and reinforcements (which also allow depleted units to rotate out, rest, and integrate replacement troops), a military force can sustain fighting for far longer.