The Kushans, an organized clan of Yue Qi nomads, made the northwest frontier of India part of their empire around 50 AD. The empire was wealthy, gaining substantial revenue by controlling most of the major Asian land trade routes. Very high quality coins made from gold earned by trading with the Roman Empire was used to pay for luxury goods such as spices, silk and metalwork.
In the later part of the third century, Kushan power declined. Chandragupta I was a princely ruler in the kingdom of Magadha. An advantageous marriage and political alliance with the Licchavis rulers brought Chandragupta I total control of the kingdom of Magadha, one of the most fertile and richest kingdoms in the heartland of the former Mauryan Empire.
Chandragupta I (r. 320-335) was succeeded by his son, Samudragupta (r. 335-380) who conquered the Kushans and other smaller kingdoms and greatly expanded the emerging Gupta Empire. Chandragupta II (r. 380-414), the son of Samudragupta, expanded the Empire even further so that the Gupta Empire was almost as large as that of the ancient and powerful Mauryan Empire.
The Gupta Empire
During the time of the Gupta Empire, Indians enjoyed a Golden Age in the arts, sciences and religion. Hinduism flowered and expanded throughout India. The Hindu epic writings of the Ramayana and the Mahabbarata were completed and spread to all in the Empire. Hindu temples and shrines were built throughout the lands ruled by the Guptas. Sanskrit poetry, drama and art grew in importance, resulting in the Gupta period to be known as the classical age of Indian culture and arts. Major scientific advances were realized in the fields of astronomy, engineering and mathematics. The decimal system of numerals, which included the concept of zero, was developed. Later, Arab traders adopted this revolutionary concept and passed this mathematical system to the Europeans.
Wars of succession and invasions from the Hunas (Ephthalite or White Huns) resulted in the gradual decline of the Gupta Empire. The Empire split up but Gupta rulers continued to rule Magadha in a minor capacity until 720.