1932 - In Poona Pact, 148 of the general electoral seats were reserved for depressed classes.
1950 - Constitutional Provisions required reservation of seats in legislatures for both SC and ST. Amendment in 1951 enabled states to reserve seats for SC / ST in educational institutions.
1953 - Backward Classes Commission set up under Kaka Kalelkar to identify OBCs. Its 1955 report failed to make a major impact.
1963 - The Supreme Court ruled that total reservation couldn't exceed 50%.
1978 - Mandal Commission set up to consider quota for disadvantaged castes. It proposed reserving 27% seats for OBCs.
1989 - Former Prime Minister VP Singh announces implementation of Mandal recommendations in government jobs. It met with widespread resistance.
1992 - Apex Court upheld 27% reservation for OBCs subject exclusion of creamy layer. Proposal accepted in 1993.
2006 - HRD ministry proposes to raise reservation in educational institutions to 49.5%. Prime Minister Manmohan Singh talks about affirmative action in private sector.