The Harappa civilization of the Indus Valley collapsed in about 1500 BCE. This marked the beginning of the Vedic age. This is when a nomadic tribe entered India through the Khyber Pass. These settlers were nomads from Central Asia, who traveled to northwestern India. When they intermarried with the local people they began to call themselves Aryans. They traveled by horse. The Aryans lived among the people who were already in this region. They became farmers. They were the people that declared cattle sacred and forbid them to be used as food. They grew cotton, which they traded with other civilizations. The lack of a good road system might have hampered trade, but river navigation existed. This allowed trade among civilizations both locally and regionally. Coins were not available at this time so this meant that they traded by bartering. The Aryans traded crops and cattle for iron. Trade allowed citizens to barter for their needs and trade their excess. There were drawbacks such as it was dangerous. Outlying kingdoms were vulnerable to invasion. Another possible danger was that groups that traded with one another might become too dependent on each other for necessary goods. A good example of a necessary good sought by the Aryans was iron. The use of iron had many benefits. The Aryans used it to make stronger tools and weapons. Stronger plows meant a bigger harvest. Stronger weapons made defense easier. Trade not only brought necessary goods like iron to the Aryans, it also exposed them to different cultures. They gained much knowledge through their trade and travels, which they brought home to India and made their own. A good example of this is Hinduism. Hinduism began with the Aryan people of the Indus Valley. The Vedic Age gets its name from the four Vedas, or books of knowledge that were written during this time. The four books are called Rig Veda, Yajur Veda, Sama Veda and Atharva Veda. The Rig Veda is the oldest work of literature known to man. These four books record the hymns and prayers of the Hindu religion. Hinduism grew out of the religious customs of many people over thousands of years. This might explain why Hinduism has so many deities (polytheistic). The Hindu religion gets its name from the Indus River. There is one supreme god, Brahma, who comes in many different forms and has many names. Instead, Hinduism is about following a way of life. Hindus believe in reincarnation. This is the idea that people come back to life after they die. Hindus believe that when people die, they will come back as another life form. This form could be a person, an animal, or a plant. Hindus also believe in karma. Karma is the actions of a person. A person’s actions, or karma, determine the form they will take in their next life. The caste system was developed to keep the Aryan people in control and is part of the Hindu religion. A caste is a social group that someone is born into and cannot change. The caste system dictates which type of job you can hold, who you can marry, and with whom you can associate. The caste system separated people and set the rules for everyone’s behavior. Obeying the caste system was very important. The caste system and the law of karma are closely related. The cycle of birth, life, death, and rebirth continues many times during reincarnation. The ultimate goal of the Hindu is to achieve moksha, the state where a person’s soul is freed from the repeating cycle. Moksha is reached when a person stops wanting and becomes content with what has been given. After reaching moksha, a person’s soul becomes one with Brahman. As Hinduism expanded, the people of India who did not believe in Brahmanism formed their own religions. They did not approve of the complex rituals and animal sacrifices of Brahmanism that continued in Hinduism. Nor did they like the caste system. One of these ways was Buddhism. Buddhists did not believe in the Hindu gods and goddesses or in any godlike being. Neither did they agree with the caste system. Buddhist tradition says that Siddhartha Gautama learned what life is all about by meditating. Then, when he was named Buddha, he spent the rest of his life teaching others. Siddhartha Gautama grew up in a palace as a prince, isolated from common people. At the age of 29, Siddhartha decided to explore the world outside the palace gates. What he witnessed had a strong impact on him. Seeking answers, Gautama sat down under a fig tree and began to meditate. He would stay there for 49 days. When he finished, he claimed to have found the steps to end suffering. He was now called the Buddha—the Enlightened One- by his followers. He gave up his life as a prince to live simpler life and share his faith. Buddhist nuns and monks (missionaries) carried the teachings of Buddha on trade routes after his death. In 268 BCE, the the Mauryan Empire controlled most of Afghanistan, Baluchistan, and India. The Mauryan Emperor at this time was Asoka. In 261 BCE, he fought a long, terrible war. This war increased the amount of land in the Mauryan Empire. Asoka converted to Buddhism following the war. From this point on, he rejected violence. He gave up eating most types of meat. He also limited Hindu animal sacrifices. Asoka made Buddhism the official religion of the Mauryan Empire. He spread Buddhism by sending missionaries people on religious missions tolerance to other religions. Asoka also constructed roads, hospitals, and rest houses for his people. The Gupta dynasty replaced the Mauryan Empire. Chandra Gupta I created the dynasty, which began in Magadha at the center of the Mauryan Empire. He gained this land as a result of his marriage to a princess. Both families had held lands next to one another. The marriage created a new kingdom. The Gupta period was known as the "Golden Age" of ancient India. The economy was strong. Individual cities and villages were able to make their own economic decisions. Farmers grew wheat, rice, and other farm crops and sold them locally. Goods such as cloth, pottery, and jewelry were produced by artisans and merchants. Advances were also made in math during this period. Mathematicians of the Gupta Empire created the number system we use today. These numerals are called Arabic, however. This is because the Arabs were the ones to carry the numerals from India to the Middle East and Europe. Indian scholars created the idea of zero. They also developed the decimal system based on ten digits, which we use today. Indian mathematicians were also able to figure out the length of the year and calculated the value of pi. There were also medical advances during this period. Indian doctors used herbs and other medicines to treat disease. They could set bones and perform simple surgeries. They also began vaccinating people against smallpox. The Indian system of medicine, the oldest in the world, was called Ayurveda. Gupta workers were also skilled at metallurgy (preparing metals for use). The arts (painting, sculptures, dance, music, metal working) were also encouraged during the Golden Age of Chandra Gupta.