As I noted here, the Bharatiya Janata Party (BJP) was a rising force in Indian politics in the 1990s. Before that, India had never had a two-party system. The Indian National Congress governed, except during short periods when particularly fierce opposition to Congress had brought its opponents into ad hoc coalitions.
The 1996 general election was the first in which the BJP won the highest number of seats in the Lok Sabha, the lower house of India's federal parliament. But a would-be BJP government died aborning, when it failed to build a sufficient coalition.
After two years of shifting coalitions, backed from behind the scenes by Congress, India faced another general election in 1998. This time, the BJP, which again finished first, was able to construct a coalition government with its leader, Atal Bihari Vajpayee, as prime minister.
Vajpayee and his party survived some continued instability. The withdrawal of a coalition partner forced another general election in 1999. The BJP strengthened its parliamentary position, and was finally able to build a long-term coalition.
In the meantime, the Nehru dynasty re-emerged within the Congress Party. Rajiv Gandhi's widow, Sonia Gandhi, took over the Congress leadership in 1998. She was controversial for at least two reasons: 1) she was associated with the controversies of the three Nehru-Gandhi prime ministers; and 2) she was a native of Italy, who did not become an Indian citizen until 1983, 15 years after she married Rajiv.
The economic boom that had begun in the early '90s continued through the period of BJP government. Therefore, that party confidently approached the next general election, in 2004. But they turned out to be overconfident.
In a surprise result, Congress won the highest number of seats in 2004, and that party and its allies were able to form a governing coalition. Sonia Gandhi declined to take the post of prime minister, which instead went to Manmohan Singh, who had been the architect of India's first major economic reforms, as finance minister in the early 1990s.
Arguably, that was the point when modern India became a mature democracy. For the first time, the voters threw out one viable coalition, and replaced it with another. As of now, it's not (yet, at least) clear that a stable two-party system is firmly in place, but India has come closer than ever to that situation.
Next: The dynasty looks likely to continue to the next generation but, as is the case with so many families, not all of the Gandhis are on good terms with each other.