1. Roman and Greek traders frequented the ancient Tamil country and forged trade relationship with ancient kings of Pandiya, Chola and Chera dynasties.
2. Cholas had a strong trading relationship with Chinese Song Dynasty.
3. The Cholas conquered the Sri Vijaya Empire of Indonesia and Malaysia to secure a sea trading route to China.
4. During the 16^th and 18^th centuries, India's overseas trade expanded due to trading with European companies.
5. The discovery of new all-sea routes from Europe to India via Cape of Good Hope by Vasco da Gama had far-reaching impact on the civilized world.
6. The arrival of Portuguese in India was followed by the advent of other European communities
7. India's maritime trade was a monopolized one over Europeans and at one stage the global trade share of India was 55 percent which is just 2 percent in 21^st  century.
8. The European merchants who came to India were not only individual merchants but also represented their respective governments.
9. They gained a strong foothold in India's maritime trade by virtue of their strong naval power.
10. In course of time their commercial motives turned into territorial ambition like the East India Company which became the British Empire here.
11. Textiles and ship building earned name and fame in the 17th and 18th centuries.
12. Britishers gradually abolished Princely order in the Indian territories.
13. Thus the demand for Indian goods declined during the British rule.
14. Britishers put in place policies prohibiting the export of some of the popular goods like Indian textile goods, handicrafts to Great Britain.
15. Between early 1600 and mid-19th century, the British East India company led establishment and expansion of foreign trade all over Asia.
16. Although initial interest of the East India Company was aimed at reaping profits, their single minded focus on establishing a trade monopoly throughout Asia Pacific made them heralding agent of British Colonial Imperialism.

Coastal Trade in Ancient Tamil Nadu:
1. Big cities like Poompuhar had the 'Maruvurappakam' (inland town) and 'Pattinapakkam' (coastal Town) had market and bazaars where many merchants met one another for the purpose of selling or buying different kinds of commodities and food stuff.
2. Port towns like Tondi, Korkai, Puhar and Muziri were always seen as busy with marts and markets with activities related to imports and exports.
3. In such a brisk trade, people of the coastal region, engaged themselves in coastal trade and developed their intercontinental trade contacts.
4. They were engaged in different kinds of fishing pearls, and conches and produced salts and built ships.
5. Boats like 'Padagu', 'Thimil', "Thoni', 'Ambu' 'Odampunai', etc... were used to cross rivers for domestic trade while Kalam, Marakalam, Vangam, Navai, etc.. were used for crossing oceans for foreign trade.

Commerce and Trade in North India:
1. India was prosperous even during medieval period from 12th to 16th centuries despite political upheavals.
2. Balban was first sultan who paved the way in the dense forest and helped traders and their commercial caravans to move from one market place to others.
3. Alauddin Khilij brought the price to a very low ebb.
4. He encouraged import of foreign goods from Persia and subsidised the goods.
5. Arabs were dominant players in India's foreign trade.
6. They never discouraged Indian traders like Tamils, Gujaratis, etc.
7. The trade between the coastal ports were in the hands of Marwaris and Gujaratis.
8. The overland trade with central and west Asia was in the hands of Multanis who were Hindus and Khurasanis who were Afghans, Iranians and so on.
9. During Sultanate period, trade flourished due to the establishment of currency system based on silver and copper.
10. Moorish traveller described the teeming market of big cities in the Gangetic plains, Malwar, Gujarat and South India.
11. The important trade centres were Delhi, Mumbai, Ahmedabad, Sonar, Sonargoon, Jaunpur, Lahore and so on. The burgeoning foreign trade led to the development of market place in the towns and villages.
12. India's handicraft commanded a good foreign market. India imported horses, dry fruits, precious stones, glassware, high grade textiles, raw silk, corals, scented oil, velvets, etc.. from Kabul, Arabia, Europe, West Asia and China.
13. Indian products were exported to East Africa, Malaya, China and Far East.
14. Trade was conducted through overland routes with Afghanistan, Central Asia and Persia. India conducted foreign trade via land route with Quetta, Khyber pass, Iraq and Bukhara.
15. The traders of Malabar, Gujarat and foreign settlers in the ports of Calicut, Khumbat and Mangalore controlled a major business sector in port cities.

The barter system envisages mutual exchange of one's goods to other without the intervention of money as a medium of exchange. It imposes certain constraints in the smooth flow of trade as explained below.
Lack of Double Coincidence of Wants:
Unless two persons who have surplus have the demand for the goods possessed by each other, barter could not materialize. For instance 'A' is having a surplus of groundnut and 'B' is possessing rice in surplus. In this case A should be in need of rice possessed by B as the latter should desperately need groundnut possessed by A. If this "coincidence of wants" does not exist, Barter cannot take place.
Non - Existence of Common Measure of Value:
Barter system could not determine the value of commodities to be exchanged as they lacked commonly acceptable measures to evaluate each and every commodity. It was difficult to compare the values of all articles in the absence of an acceptable medium of exchange.
Lack of Direct Contact between Producer and Consumers:
It was not possible for buyers and sellers to meet face to face in many contexts for exchanging the commodities for commodities. This hindered the process of barter in all practical sense.
Lack of Surplus Stock:
Absence of surplus stock was one of the impediments in barter system. If the buyers and sellers do not have surplus then no barter was possible.

The passage of goods and services between the producer and the consumer is best with many hindrances and some of them are as follows:
Hindrance of person:
1. Manufacturers do not know the place and face of the consumers.
2. It is the retailer who knows the taste, preference and location of the consumers.
3. The chain of middlemen consisting of wholesalers, agents and retailers establish the link between the producers and consumers.
Hindrance of place:
1. Production takes place in one centre and consumers are spread throughout the country and world.
2. Rail, air, sea and land transports bring the products to the place of consumer.
Hindrance of time:
1. Consumers want products whenever they have money, time and willingness to buy.
2. Goods are produced in anticipation of such demands.
3. They are stored in warehouses in different regional centres so that they can be distributed at the right time to the consumers.
Hindrance of risk of deterioration in quality:
1. Proper packaging and modern air conditioned storage houses ensure that there is no deterioration in quality of products.
2. Goods are protected against insects, rats, evaporation etc..
Hindrance of risk of loss:
1. Fire, theft, floods and accidents may bring huge loss to the business.
2. Insurance companies serve to cover the risk of such losses.
Hindrance of knowledge:
Advertising and communication help in announcing the arrival of new products and their uses to the people.
Hindrance of exchange:
Money functions as a medium of exchange and enable the buying and selling of any product or service by payment of the right price.
Hindrance of finance:
1. Producers and traders may not have the required funds at the time of their need.
2. Banks and other financial institutions provide funds and help in transfer of funds to enable the functioning of business smoothly.
Hindrance of developing the exact product:
Research and development helps in developing the exact product or service which can satisfy the specific wants of consumers and. thus improve the standard of living of the people.
Hindrance of both selection and delivery at doorsteps:
E-Commerce enables the consumer to select the product in the website, place online orders and make payment after receiving the product at the door step.