The shoe is a form of footwear that covers the foot up to the ankle and that is intended as a protection from cold, dampness, or rough terrain. In addition to shoes, other basic types of footwear are sandals, moccasins, boots, slippers, and mules. The sandal has a flat sole of leather or wood fastened to the foot by straps, thongs, or a knob between the toes. The moccasin is distinguished by a sole that extends up around the foot to form some part or all of the upper section of the shoe. This is a primitive form of footwear that is still worn by hunters because of its flexibility and because it gives greater protection against dampness than shoes with a seam between the sole and the uppers. The boot consists of a sole and an upper part that extends above the ankle to protect the leg from cold, wetness, or dangerous conditions, such as snakebite or thorny giants. The slipper is a soft shoe, often intended for indoor wear, with uppers generally made of fabric and sometimes lined for winter wear with wool or fur. Mules are slippers that consist of a sole and an upper that covers only the toes.
Shoes have been made of various substances, depending on the raw material available and the varying climatic conditions in different parts of the world. Thus wooden shoes were worn in forested Europe; clogs (wooden soles with straps for support) in the warm Middle East, India, and Japan; tree bark moccasins in Scandinavia; and straw sandals and fabric shoes in Korea and China. The people of predominantly cold countries have always worn high boots, of which Russian boots in black or red leather are typical. The Laplanders' boots have moccasin feet with turned-up toes, and the people of Tibet, Bhutan, and Nepal in the Himalaya wear high boots made from the skin of the hairy yak.
Leather has been the principal material for making shoes. Undoubtedly the first material used for shoes and the most widely available, leather has also proved to have the most suitable qualities. Stone Age man was unable to cover himself with any other material as large as the skin of the animal he had killed for food, and it is probable that he also wrapped pieces of hide around his feet to protect them against the cold, the rough ground, or the sharp shards of flint from which he made his tools. When the hide dried and cracked, primitive man softened It with animal oils and fats, the first effort at leather dressing.
With the dawning of personal vanity, man began to experiment with vegetable dyes to alter the color of his skin clothes. In so doing, he chanced upon a method of preserving the hide from putrefying and by accident turned it into leather. Dressing and curing hides by natural oils and vegetable dyes were practiced until the 20th century, when tanning came to be done chemically with chromium salts. Vulcanized rubber has been increasingly used for footwear in the 20th century. Synthetic rubber, discovered during World War II by Waldo Semon, is now the most important shoemaking material, providing hardwearing, waterproof soles. Also, plastics are used, especially for uppers.
Shoes have always been made on a molded shape called a last, traditionally of maple wood, but now often made of plastic or aluminum. A wooden last of the Neolithic Period was found in Switzerland, and many iron lasts made by the Romans have been dug up in England. Complicated machinery has been made to perform every process that was formerly done by hand in the making of a shoe, but great skill is still needed on the part of the operator to turn out a satisfactory machine-made article.
Until the age of cheap mass production, shoes were generally considered a mark of rank or prestige. Common men walked barefoot, and their feet became calloused, helping them to escape much of the discomfort that would result from not wearing shoes. The nobility, on the other hand, felt obliged to wear shoes as a proof of gentility, that they could not bear roughness or dirt. In China, in order to indicate their incapacity for physical work, upper-class parents bound their daughters' feet to prevent normal growth and to produce a small, twisted "lily foot". As a result, wealthy Chinese women could scarcely walk in their tiny shoes.