The kings of India up to Mahārāja Parīkṣit were able to rule the entire world, and not for a mere couple of centuries but for hundreds of thousands of years. The reason for their rule was not a political one.
India's wise men of yore easily realized that the threefold miseries we humans are condemned to suffer can never be mitigated by the political condition controlling the country—whether foreign rule or freedom from it. At the dawn of modern history, the Armageddon fought in India over a political question lasted only eighteen days. On that historic battlefield the problem of human suffering and its permanent solution was discussed, and this discussion was compiled in the form of the Bhagavad-gītā.