Bharatiya Jana Sangh
The Bharatiya Jana Sangh ( BJS or JS, short name: Jan Sangh, was an Indian right wing nationalist political party that existed from 1951 to 1977 and was the political arm of Rashtriya Swayamsevak Sangh (RSS), a Hindu nationalist volunteer organisation. In 1977, it merged with several other left, centre and right parties opposed to the Indian National Congress and formed the Janata Party. After Janata Party's defeat in 1980 Lok Sabha polls, Advani and Vajpayee, the last two presidents of Jana Sangh, initiated moves to resuscitate Jan Sangh; but this time the new grouping took the name Bharatiya Janata Party. Origins

Many members of the right-wing Hindu nationalist Rashtriya Swayamsevak Sangh (RSS) began to contemplate  the formation of a political party to continue their work, begun in the days of the British Raj, and take their ideology further. Around the same time, Syama Prasad Mukherjee left the Hindu Mahasabha political party that he had once led because of a disagreement with that party over permitting non-Hindu membership. The BJS was subsequently started by Mukherjee on 21 October 1951 in Delhi, with the collaboration of the RSS, as a "nationalistic alternative" to the Congress Party. After the death of Mukherjee in 1953, RSS activists in the BJS edged out the career politicians and made it a political arm of the RSS and an integral part of the RSS family of organisations (Sangh Parivar). The strongest election performance of the BJS came in the 1967 Lok Sabha election in which it won 35 seats, when the Congress majority was its thinnest ever. Ideology

The BJS leadership strongly supported a stringent policy against Pakistan and China, and were averse to the USSR and communism. Many BJS leaders also inaugurated the drive to ban cow slaughter nationwide in the early 1960s. Chronological list of presidents

In general elections 
The Bharatiya Jana Sangh was created in 1951, and the first general election it contested was in 1951–52, in which it won only three Lok Sabha seats, in line with the four seats won by Hindu Mahasabha and three seats won by Ram Rajya Parishad. Shyama Prasad Mookerjee and Durga Charan Banerjee were elected from Bengal and Uma Shankar Trivedi from Rajasthan. All the like-minded parties formed a block in the Parliament, led by Shyama Prasad Mookerjee. 