After the temporary conquest of northwest India by Alexander the Great in 326 B.C., the Maurya Empire was established and in time spread over all India and parts of central Asia. The most famous Maurya ruler was King Asoka (272-232 B.C.), some of whose great stone pillars, erected in every important city in India of his day, still stand. These pillars are of interest to us because, as stated in Section 1-9, some of them contain the earliest preserved specimens of our present number symbols.
After Asoka, India underwent a series of invasions, which were finally followed by the Gupta dynasty under the rule of native Indian emperors. The Gupta period proved to be the golden age of the Sanskrit renaissance and India became a canter of learning, art and medicine. Rich cities grew up and universities were founded. The first important astronomical work the anonymous Surya Siddhanta (“ knowledge from the sun”), dates from this period, probably about the beginning of the fifth century. Hindu mathematics from here on becomes subservient to astronomy rather than religion. In the sixth century work, Panca Siddhanta, of the astronomer varahamihira and based on the earlier Surya Siddhanta , is found a good summary of early Hindu trigonometry and a table of sines apparently derived from Ptolemy’s table of chords.