Trade and commerce in early ancient India was not confined to the composite Vaisya class. The lawful occupations of the Vaisyas according to various Dhannasutras, besides study, sacrifice and Dana, were agriculture, trade and cattle breeding.
Some added banking and art (shilpa) to the above mentioned functions of the Vaisyas. Gradually, however, due to the flexibility of Vamasramadhar- rules, the Brahmins and the Kshatriyas also joined trade and commerce along with the Vaisyas.
Buddhist literature has several references which show that the Brahmins, as well as the Kshatriyas accepted the trading profession not only in times qf distress but also in ordinary circumstances.
To avoid intrusion by other Vamas into their business and occupational monopoly, the Vaisyas created new organisations like Sreni, Nigama, Puga, Sarthavaha, etc. These organisations formulated their own rules and regulations for the guidance of their business conduct known as Samaya and Srenidhantta.
The coming of the foreigners after Alexander’s invasion and establishment of the Yavana dynasties in various parts of India, after the decline of the Mauryas, was of vital importance in the development of ancient Indian trade. Under the Indo-Greeks or Greco-Bactrians, Shakas, Kushanas, etc. trade centres like Kapisa, Taxila, Puskalavati, Vidisha, etc. prospered. The Indo- Greek King Menander patronised trade emporiums of Sagala (Sakala) where traders from different places assembled.
Similarly, in the territory of the Shakas there were trade centres of Kapisa, Taxila, Pus- kalavati and Mathura. Under the Kushanas, Indian trade made considerable progress and Kushana traders established trade relations with China, Rome, Sindhu, Sauvira, Kapisa, Gandhara, Puskalavati, etc.
In the early centuries of the Christian era, trade centres of Vidisha, Ujjaini, Bharukachchha, Surparaka, Prabhasa, Dasapura and Nasika were under the occupation of West ern Kshatrapas. These foreign merchants were also absorbed among the Indian trading communities, and there was no rivalry between the Indian traders and those coming from abroad.