The Prime Minister of India during 1977-79 was Morarji Desai.

Explanation:
Morarji Desai served as the Prime Minister of India from 1977 to 1979. Let's look at the background and events leading up to his tenure as Prime Minister:

1. Background:
Morarji Desai was born on February 29, 1896, in Bhadeli, Gujarat, India. He had a long and distinguished political career, beginning with his involvement in the Indian independence movement. Desai was a prominent member of the Indian National Congress and played an active role in the fight for independence from British rule.

2. Emergency and Indira Gandhi's rule:
In 1975, then Prime Minister Indira Gandhi declared a state of emergency, suspending civil liberties and imposing strict censorship. This move was met with widespread opposition and protests from various political parties and civil society groups. The emergency lasted for 21 months until it was lifted in 1977.

3. General Elections of 1977:
Following the lifting of the emergency, general elections were held in 1977. This election is often referred to as the "Janata Wave" as it saw a significant shift in the political landscape of the country. The Janata Party, a coalition of several opposition parties, emerged victorious, ending Indira Gandhi's rule.

4. Formation of Janata Party government:
As a result of the elections, a coalition government was formed under the leadership of Morarji Desai. The Janata Party comprised several political parties, including the Bharatiya Lok Dal, the Bharatiya Jana Sangh, and the Congress (O). Morarji Desai became the first non-Congress Prime Minister of India.

5. Morarji Desai's tenure as Prime Minister:
Morarji Desai's tenure as Prime Minister was marked by his emphasis on austerity measures, decentralization, and anti-corruption efforts. He implemented various economic reforms and policies aimed at promoting self-reliance and reducing government control. However, his government faced numerous challenges, including internal disagreements within the Janata Party coalition, which eventually led to its dissolution and the end of Morarji Desai's term as Prime Minister in 1979.

In conclusion, Morarji Desai served as the Prime Minister of India from 1977 to 1979. His tenure was significant as it marked the end of Indira Gandhi's rule and the beginning of a new era in Indian politics.