It was the year 1988 when an alliance against the Congress Party took shape in the form of NDA. By that time the phase of majority for one party had passed. Which was called Congress System by a famous political scientist. This was the beginning of the era of alliance. Earlier in the 90s itself, two coalition governments each of National Front and United Front had fallen. Read More - https://www.prabhasakshi.com/infographs/bharat-vs-india-political-alliance