J.swaminathan was born in Sanjauli, Simla, on June 21, 1928. He was the sizth child ( among 11 others) of Rao sahib N.V. Jagadisa Iyer and his wife Saraswati. Jagadisa Iyer was the private secretary to the Commerce Member Of the Vice Regal Council. Swaminathan, by his own account, was an unruly, mischievous and self willed boy loved to draw and paint. He studied at the Sir Harcourt Butler High School in Delhi and Simla where his sketches of nationalist leaders adorned the school walls. 1942 the year of his matriculation-coincided with the start of the Quit India struggle. The next year, Swaminathan dropped out his Pre-Medical course at Delhi Hindu College, Sold his Bicycle and ran away to Calcutta where he was inspired by some revolutionaries to join the Congress Socialist Party (CSP) lead by Jaya Prakash Narayan, Rammanohar Lohiya and Aruna Asaf Ali.
At a public meeting he saw Bhawani Pande, the sister of a socialist comrade, and fell in love. They married in Lucknow in 1955.
As a full time cadre of the CSP he was (by 1946) a Member of its Delhi Executive and Edited its Hindi Journal "Majdoor Awaaz" (Worker's Voice). After Independence in 1947 when the CSP was splintering, Swaminathan had radicalized to the point of differing strongly with Jaya Prakash Narayan. In 1948, along with Aruna Asaf Ali, Edathatta Narayanan and others, he joined the Communist Party of India (CPI) as a whole timer.
During the First General Elections of 1952/53, Swaminathan was active as a CPI activist in Delhi and Punjab. After the Soviet takeover of Hungary in 1956 he got disillusioned with both the Communist Party and politics itself.
Pursuing his childhood passion for painting, he joined the evening classes at the Delhi Polytechnic where he came under the spell of Sailoz Mukherjee, the bohemian artist and teacher who was a source of inspiration to a whole generation of Delhi artists.
In 1958-59 Swaminathan went to Warsaw, Poland for a year to study Graphic Art at the Academy of Fine Arts. Returning to India he joined the Link, a Magazine. Link was India's first news weekly founded by Aruna Asaf Ali with Edathatta Narayanan as its editor. Swaminathan was reporting on south and South-East Asia, designing the cover and writing on art.
Between 1960 and 1965 he exhibited his works in several solo and group exhibitions.
Between 1960 and 1993/4 swaminathan held thirty one men shows and participated in too many groups exhibitions to enumerate here.
In 1962 he Eleven Other artists formed the Group 1890 in Bhavnagar, Gujrat. Their first and only showing together was held in august 1963 when it was introduced by the then Maxican Embassador and Poet Octavio Paz and inaugurated by Prime Minister Jawahar Lal Nehru at the Newly opened Rabindra Bhawana Galleries of the Lalit Kala Akademi.
Swaminathan strongly rejected all derivate or fashionable 'isms' , specially the long shadow of the already much dated ecole de Paris on modern Indian art. As only and Ex-Marxist could, right from the 1963 manifesto of Group 1890, he argued:
"Art for us is not born out of a preoccupation with the human condition. We do not sign of a man ,nor we his messiahs. The function of art is not to interpret and annotate, comprehend or guid.such attitudinising mat seem heroic in an age when man, caught up in the mesh of his own civilization, hunger for vindication. Essentially, this self glorification to us is but the perpetuation of the death wish, of the sate of unfreedom of man. Art is neither conformity of reality nor a flight from it. It is reality itself a whole new world of experience, the threshold for the passage into the sate of freedom."
From his early 'cave painting' like canvasses of the early 1960s he moved to the wall paintings of folk and tantric art .Through the symbol of the sperm, the lingam and the yoni he explored what the British critic and later a fellow of the Royal collage, Philip Rawson called the 'Traditonal Numen' in the context of reviewing Art now in India and exhibition curated by George Butcher, the critic of 'The Guardian' , for the commonwealth institute in 1964. This preceded the publication of Ajit Mukharjee's work and later this style of painting was to develop as the neo-Tantric school.
In 1966 he co-edited with Octavio Paz a small art journal named contra'66. Octavio Paz wrote a poem Al Pintor swaminathan on him the same year. He studied the colour arrangement in Pahari miniatures to develop a pictorial vocabulary that he called the 'colour Geometry of Space' . Within a couple of years that led to his famous and resplendent landscapes titled Bird -Tree-Mountain series that lasted till mind 1980s . In his last years he returned to the tribal wall paintings style that he had explored in the year 1960s.
During 1967/68 he awarded the Nehru Fellowship to research the "significance of the Traditional Numen" in folk and tribal Indian Art.
In 1969 he was invited to be jury of the Sao Paolo Biennale and visited Mexico and New York .From the 70s Swaminathan was an important figure in the Indian Art scene and served in several organizations and committees of the Government of India including the ITDC, ICCR, LKA, Crafts Museum, Festivals of India.