After the downfall of Maurya Dynasty, India,specially north India, was divided in small kingdoms. But so,me dynasties in south continued to rule for centuries but they could not unite India as Mauryas had done.It was the Gupta dynasty that emerged as a major power in the early years of fourth century and united India into a nation. Gupta Empire's time is also cosidered to be the golden age of India as India was at its peak in the fields of science, mathematics, astronomy, religion, Indian Philosophy and literature during their reign. Kalidas and Aryabhatta are the two famous figures of that time.It was Aryabhatta who had first claimed that earth revolves around the sun. He also gave the concept of zeroto the world.He had contributed a lot to Mathemeticsalso.He has been discovered that he knew about the concept of pie (22/7) also.Kalidas was a playwright who had written 'Shakuntala.'.Indian literature of that age has influenced the Greek literature a lot.