The Prime Minister Narendra Modi has become the longest-serving non-Congress PM (From 26 May 2014) of the country as on August 13th.
And also, he has also been at the helm of an elected government for a period of 18 years, which is the longest such tenure by the head of the government.
This includes his term as the Chief Minister of Gujarat (7 October 2001 to 22 May 2014) before assuming the charge of the PM of the country in the year 2014.
The Prime Minister has completed his term as the Chief Minister and now as the PM for over 18 years and 306 days.
Before this, the first PM of India, Nehru served as the PM of the country for a period of 16 years and 286 days.
Indira Gandhi had the third-longest tenure as the head of the elected government in the country with a length of 15 years and 350 days as the Prime Minister.
Jawaharlal Nehru, Indira Gandhi and Manmohan Singh - all from the Congress - are the three longest serving Prime Ministers in that order.