Traditionally, shoes have been made from leather, wood or canvas, but in the 2010s, they are increasingly made from rubber, plastics, and other petrochemical-derived materials. Though the human foot is adapted to varied terrain and climate conditions, it is still vulnerable to environmental hazards such as sharp rocks and hot ground, which shoes protect against. Some shoes are worn as safety equipment, such as steel-soled boots which are required on construction sites.
The earliest known shoes are sandals dating from approximately 7000 or 8000 BC, found in the Fort Rock Cave in the US state of Oregon in 1938. The world's oldest leather shoe, made from a single piece of cowhide laced with a leather cord along seams at the front and back, was found in the Areni-1 cave complex in Armenia in 2008 and is believed to date to 3500 BC. tzi the Iceman's shoes, dating to 3300 BC, featured brown bearskin bases, deerskin side panels, and a bark-string net, which pulled tight around the foot. The Jotunheimen shoe was discovered in August 2006. Archaeologists estimate that the leather shoe was made between 1800 and 1100 BC, making it the oldest article of clothing discovered in Scandinavia.
It is thought that shoes may have been used long before this, but because the materials used were highly perishable, it is difficult to find evidence of the earliest footwear. By studying the bones of the smaller toes (as opposed to the big toe), it was observed that their thickness decreased approximately 40,000 to 26,000 years ago. This led archaeologists to deduce that wearing shoes resulted in less bone growth, resulting in shorter, thinner toes. These earliest designs were very simple in design, often mere "foot bags" of leather to protect the feet from rocks, debris, and cold. They were more commonly found in colder climates.
Many early natives in North America wore a similar type of footwear, known as the moccasin. These are tight-fitting, soft-soled shoes typically made out of leather or bison hides. Many moccasins were also decorated with various beads and other adornments. Moccasins were not designed to be waterproof, and in wet weather and warm summer months, most Native Americans went barefoot.
As civilizations began to develop, thong sandals (the precursors of the modern flip-flop) were worn. This practice dates back to pictures of them in ancient Egyptian murals from 4000 BC. One pair found in Europe was made of papyrus leaves and dated to be approximately 1,500 years old. They were also worn in Jerusalem during the first century of the Common Era. Thong sandals were worn by many civilizations and made from a wide variety of materials. Ancient Egyptian sandals were made from papyrus and palm leaves. The Masai of Africa made them out of rawhide. In India they were made from wood. In China and Japan, rice straw was used. The leaves of the sisal plant were used to make twine for sandals in South America while the natives of Mexico used the Yucca plant.
While thong sandals were commonly worn, many people in ancient times, such as the Egyptians, Hindus and Greeks, saw little need for footwear, and most of the time, preferred being barefoot. The Egyptians and Hindus made some use of ornamental footwear, such as a soleless sandal known as a "Cleopatra", which did not provide any practical protection for the foot. The ancient Greeks largely viewed footwear as self-indulgent, unaesthetic and unnecessary. Shoes were primarily worn in the theater, as a means of increasing stature, and many preferred to go barefoot. Athletes in the Ancient Olympic Games participated barefoot and naked. Even the gods and heroes were primarily depicted barefoot, and the hoplite warriors fought battles in bare feet and Alexander the Great conquered his vast empire with barefoot armies. The runners of Ancient Greece are also believed to have run barefoot. Pheidippides, the first marathoner, ran from Athens to Sparta in less than 36 hours. After the Battle of Marathon, he ran straight from the battlefield to Athens to inform the Athenians of the news.
The Romans, who eventually conquered the Greeks and adopted many aspects of their culture, did not adopt the Greek perception of footwear and clothing. Roman clothing was seen as a sign of power, and footwear was seen as a necessity of living in a civilized world, although the slaves and paupers usually went barefoot. Roman soldiers were issued with chiral footwear. There are references to shoes being worn in the Bible.