Footwear has had a complex and rich development throughout history. I imagine it came about first to protect from searing sands in the desert and frozen snows in the tundra. As people moved from the state of primitive humans who lead nomadic existences tromping through bush and forest, to homo erectus and started building societies and homes, they started to differentiate and specialize themselves.
Feet probably got a little softer, and hard packed ground or stones started to be felt more, now that the homo habilis callouses were gone. Cold, rain, heat, rocks, mud: all these became reasons to start sheathing the feet. And what’s supple enough to fit around the odd shape of a foot, or a human body for that matter? Skin. Leather.
So shoes began and continue to this day. In some cases cloth was used for shoes but almost exclusively for indoor or court occasions as the material couldn’t stand up to the rigors of hard travel. The simplest and earliest shoes were scraps of leather. Then they were leather, which was cut, punched and tied around the feet. The Irish/Scottish gillies were a piece of leather cut in such a way that it drew up around your foot. A more styled version is used to this day in Highland dancing. In fact certain runners/tennis shoes also follow this style and shape.
These ghillies were not waterproof, having slits all the way around but they fit the foot. The Romano-Greco countries used sandals a lot because of the hot climate. The Romans also made a hobnailed shoe and boot that lasted longer for those centurions travelling to invade other lands. As both skill levels and techniques grew more complex, so did the style of the shoe. The Mongols and Huns were the first to use a shoe with a heel, developed to sit in the stirrup and stop the foot from sliding.
These shoes were all made for practical reasons. Intricate patterning and stitching came along, making better fitted shoes and boots. Cobblers learned to put thicker leather or wood on for soles, creating a longer lasting shoe that also repelled invasive elements. These methods, along with curing leather in different ways or oiling it, started the sophistication of the shoe.
And of course shoes were made for fashion. Fashion was dictated by different elements. A clubfooted king gave rise to a round toed shoe. A new dye color or pattern became popular because it was different. The pointy toed shoe of the 14th century reached such extremes of pointyness (up to two feet) that the point had to be gartered to the calf.
Pattens, a wooden clog that the shoe was slipped into, were widely used in the 15th century on muddy streets. However, nobles and those of richer means took them to ridiculous heights to show their status. The platform shoe of the 70s and later decades truly had nothing on these pattens of long ago. The most bizarre shoes were those tiny, distorted shapes of silk and wood used to bind women’s feet into diminutive monstrosities in China. A shoe for decoration only as these elite women could barely walk at all.
Mongols and other Asian races made shoes and boots of felted wool. These were very warm and very waterproof. Likewise the Inuit were using sealskin, still a leather but with the fur left on for added warmth. In most cases boots and shoes might have the fur on the inside for warmth (sheepskin) but could have it on the outside for water-repellent features or for decoration.
Shoes were slipped on, tied, buckled, buttoned and laced. There were as many ways to put them on as human minds could come up with. Though fashions of a long ago era ran narrower lines due to cost and production being done by hand, still there grew to be a great variety that continued to our cornucopia of the modern day.