Indira Gandhi is expelled — and the Congress splits in two

Through 1969, Prime Minister Indira Gandhi was at odds with the party's senior leadership — a group of state bosses known as the “Syndicate,” including party president S. Nijalingappa, K. Kamaraj, Morarji Desai and Atulya Ghosh — over control of both the party and her government. The rift widened when she pushed through the nationalisation of 14 major banks and backed V. V. Giri, running as an independent, over the official Congress candidate Neelam Sanjiva Reddy in that year's presidential election.

On 12 November 1969, the Congress leadership expelled Indira Gandhi from the party on charges of indiscipline. The organisation split immediately: the Syndicate retained the Congress name and its traditional bullock symbol as the Indian National Congress (Organisation) — Congress(O) — while the majority of the party's own committee, 446 of 705 members of the All India Congress Committee by most accounts, sided with Indira Gandhi, who continued as Prime Minister leading what was informally called Congress(R), for “Requisitionists.”

The 1971 Lok Sabha election settled which side voters treated as the real Congress: Indira Gandhi's faction won a landslide on the slogan “Garibi Hatao” (“Remove Poverty”), and her branch has carried the Congress name and lineage ever since — it's the INC that exists today. Congress(O) held on to power in a few states through the early 1970s before folding into the newly formed Janata Party in 1977, alongside the Bharatiya Lok Dal and the Bharatiya Jana Sangh, in the aftermath of the Emergency.