What were some key changes brought about by the Constitution (Twenty-Sixth Amendment) Act, 1971 with regard to rulers of Indian States and privy purses?
The Constitution (Twenty-Sixth Amendment) Act, 1971 brought about two key changes with regard to rulers of Indian States and privy purses:

1. Abolition of titles: With the commencement of this amendment act, the Prince, Chief or other person who was recognized by the President as the Ruler of an Indian State before the act came into effect ceased to be recognized as such Ruler or their successor.
2. Abolition of privy purse: On and from the commencement of the Constitution (Twenty-Sixth Amendment) Act, 1971, the privy purse was abolished for all rulers and their successors referred to in clause (a), as well as any other person. The rights, liabilities, and obligations in respect of privy purse were extinguished, and no sum would be paid as privy purse after that date.