In 319 AD, King Chandragupta I managed to unite all of northern India into a great empire again. (He was not related to the Mauryan Chandragupta, but he wanted people to think he was). Chandragupta I even conquered some of South India. People called him “King of Kings”, like the Iranian emperors further north. He was not Buddhist but Hindu, following the older Indian religion. Many Jains moved from eastern India to western India, across the Guptan Empire, at this time.
Chandragupta died about 335 AD. His son Samudragupta conquered even more of India and into Southeast Asia and Central Asia, leading his troops out every year to conquer more land. He may have forced the rich Sogdians (in modern Afghanistan) to pay taxes to India. Like Constantine a few years earlier, Samudragupta minted beautiful solid gold coins.
Under the Guptan kings, India was very rich and powerful, with freedom of religion unlike in Rome at the same time. Peace allowed traders to travel safely, and there was more trade between India and China, passing through Sogdiana in Central Asia. India sold high quality steel, cotton cloth, pearls, and glass beads all over East Africa and Asia. Buddhist pilgrims and Indian and Chinese scientists also traveled between China and India. This travel may have helped Indian mathematicians to make important advances in math at this time, like inventing the number zero.
They invented the game of parcheesi. Indian scientists figured out how to make sugar cane into pure crystalized sugar about 350 AD, and Indian traders started to sell sugar in China. In return, Chinese travelers brought an early version of the game of chess to India.
When Samudragupta died about 380 AD, his son Chandragupta II took over. He was even more successful than his father and grandfather. India became very rich. There were good roads, hospitals for sick people, and universities. Guptan kings liked to use marriages to rulers in other kingdoms as a way to get more power too. Chandragupta II’s daughter Prabhavati married a neighboring Indian king, Rudra Sena II, and when Rudra Sena died, Prabhabati ruled as regent for their sons.
Chandragupta II died about 415 AD. His son Kumaragupta kept the empire going until in 455 AD the Huns invaded India from the north and destroyed the Guptan Empire. Kumaragupta may have been killed. India slowly split into a bunch of smaller kingdoms including the Chola Empire and the Rajput kings.