Although preceded by two Guptan rulers, Chandragupta I (reign 320-335 CE) is credited with establishing the Gupta Empire in the Ganges River valley in about 320 CE, when he assumed the name of the founder of the Mauryan Empire. The period of Gupta rule between 300 and 600 CE has been called the Golden Age of India for its advances in science and emphasis on classical Indian art and literature. Gupta rulers acquired much of the land previously held by the Mauryan Empire, and peace and trade flourished under their rule. Sanskrit became the official court language. In 499 CE, the mathematician Aryabhata published his landmark treatise on Indian astronomy and mathematics, Aryabhatiya, which described the earth as a sphere moving around the sun.
Astronomy, astrology, mathematics, and religion were closely linked in ancient India. Astronomy developed out of the need to determine solstices, equinoxes, and phases of the moon for Vedic rituals. Eighteen early astronomical texts or siddhantas, of which only the Surya-Siddhantha, written around 400 BCE, survives, discuss topics including lunar and solar eclipses, astronomical instruments, and the phases of the moon. The Vedanga Jyotisha composed by the astronomer Lagadha about 500 BCE outlines a calendar based on a five-year cycle or yuga with 62 lunar months and 1,830 days. India's earliest calendar, the Saptarshi calendar is broken into 2,700-year cycles and a version counting back to 3076 BCE is still in use in parts of India today.
Astronomy flourished under the Gupta Empire (c. 320-550 CE) during which time Ujjain in central India emerged as a center for astronomical and mathematical research. In 499 CE, Aryabhata, an Indian astronomer and mathematician who was also head of the university at Nalanda in Magadha (an ancient region located in what is now Bihar), composed the Aryabhatiya, a significant treatise about mathematics and astronomy written in Sanskrit. Aryabhata described a spherical Earth that rotates on its own axis and the orbits of planets in relation to the sun. He dated the universe to approximately 4,320,000 years and calculated the length of the solar year. India's first space satellite, launched in 1975, was named Aryabhata in his honor.
By 550 CE, the original Gupta line had no successor and the empire disintegrated into smaller kingdoms with independent rulers. Unlike the Mauryan Empire's centralized bureaucracy, the Gupta Empire allowed defeated rulers to retain their kingdoms in return for a service, such as tribute or military assistance. Samudragupta's son Chandragupta II (r. 375–415 CE) waged a long campaign against the Shaka Satraps in western India, which gave the Guptas access to Gujarat's ports, in northwest India, and international maritime trade. Kumaragupta (r. 415–454 CE) and Skandagupta (r. c. 454–467 CE), Chandragupta II's son and grandson respectively, defended against attacks from the Central Asian Huna tribe (a branch of the Huns) that greatly weakened the empire.
(Reproduced and adapted for educational, non-commercial use only by students of Early World History, the above summary may also be found at http://www.pbs.org/thestoryofindia/)