The need for fences arose when ancient man realized that he had something worth protecting. This is commonly believed to coincide with the earliest development of agriculture. If a man was going to put the effort into preparing a field (plowing with a stick for crying out loud) sow seeds and tend the crop while it matures, he is certainly going to make every effort to ensure that nothing happens to it before he can harvest it.
At first the biggest danger was from grazing animals. The first time they showed up, our ancient planter may have tried to simply chase them away. If he had not evolved very far from the nomadic hunter stage, he probably tried to stick a spear in a few of them. The futility of this would soon be evident. While he dealt with the one in which he stuck his spear, the rest of the herd would return to eat up his crop! Besides, it would have been difficult to watch the field all day and night to chase the animals away. There had to be a way to keep them out.
Hedging The Bet
The earliest fences may have actually been thorny hedges. If it was thick and thorny enough, the hedge would keep the animals out. The problem became how to keep the hedge from growing into the field. A more controllable option was to drive thorny sticks into the ground, closely spaced enough that the animal that wanted to eat the corps could not pass through.
Once ancient man began to successfully harvest crops, he began to acquire things. A degree of treasure, if you will. Things that the people around him would begin to covet. For some it would have been a small step from coveting to marauding, and newer, stronger fences were needed. In many cases, a simple demarcation of property lines seem to have been sufficient. A simple rail fence gives a feeling of security, but would probably not turn away a determined attack. In a few cases, the scale of the fence almost seems out of proportion to the threat. Two cases would be Hadrian’s Wall across Britain and the Great Wall of China.
By strictly technical definition, these last two examples are walls as opposed to fences. A fence is a free standing structure intended to restrict movement across a boundary. Fences are generally more lightly constructed than walls, but by some definitions the structure is not a wall unless it is used in conjunction with a roof or ceiling.
The Light Fantastic
The most lightly constructed fence in comparison to its effectiveness is the barbed wire fence. Barbed wire is notorious not only for its simple effectiveness, but also for the relative lack of expense with which it is manufactured. This is due to the fact that its simple design, a core of two wires twisted together and locked at regular intervals by a sharpened barb twisted around them. This simplistic design lent itself to industrial manufacture, to the point that more borders are defined by barbed wire than all the armies in the world.
Chainwire fencing is also an intensely industrial product. It is more complex in design and manufacture than barbed-wire, but it also forms a more effective barrier. The sheets or rolls of fencing are formed by twisting the wire and then weaving the wire pieces together, giving chainwire fencing its distinctive diamond pattern. It is produced in standard length rolls, but individual rolls can be attached to one another to form unbroken lengths of fence.