A Brief History of Camouflage
All warfare is based on deception.
This idea was by no means new when Sun Tzu laid it out so eloquently in his momentous work, The Art of War, over 2,000 years ago. But it does serve to mark the point in history where deception was first documented as the cornerstone of military tactics that it still is today.
Of course, its meaning has changed over time. The original quote or at the very least, its closest English translation reads: All warfare is based on deception. Hence, when we are able to attack, we must seem unable; when using our forces, we must appear inactive; when we are near, we must make the enemy believe we are far away; when far away, we must make him believe we are near.
There's nothing in this quote that addresses personal concealment, and while most of us today take for granted that soldiers wear camo, it wasn't until thousands of years later that we fully embraced blending into the surrounding terrain as a basic tactic.
Sure, you could find the odd example of the ancient guerrilla force attaching foliage to their outfit, or of outbuildings being disguised with the same, but it wasn't until the early 1900s that the major militaries of the world began to examine its full potential.