Reality of 1975 Emergency | Darkest Period of Indian Democracy

When Prime Minister Indira Gandhi led India in the war of 1971 and we won the war, the name of Indira Gandhi spread not only in the country but also abroad. But soon time changed and Indira Gandhi started taking decisions like a Dictator. On June 25, 1975, when Indira Gandhi declared an emergency all over India in the name of internal disturbance, the whole of India was forced to follow only and only on the instructions of the Prime Minister. What was the truth of this emergency which lasted for 21 months? Why in India even today the emergency of 1975 is called the darkest phase of Indian democracy?