A Jagdish Swaminathan show is a rare event. The National Gallery of Modern Art has been threatening one for ages, and we're still holding our breath. But don't walk into Gallery Espace expecting to see the artist in his prime. His famous bird, mountain and tree paintings take up just one wall. On display are works from a little-known period spanning roughly two decades from 1950 to 1969. Those were the years that saw him transform from a Communist Party "wholetimer" (as committed party comrades were called) to a full-time painter.

The artist's journey is mapped through photos and postcards, sketches and letters. "After my mother died and the house was about to be sold, I found a lot of material in old cartons and wrapped up bedsheets. It's taken years of sifting, " says his son, the art critic S Kalidas, who has curated this archival show.

Swaminathan died in 1992. The arc tracing his oeuvre starts with what the curator calls "aham", an inner and more personal space. There are early portraits that Swami painted of his wife, brother and household help as well as photographs of his children and postcards from his travels in Warsaw where he went to study art and do some serious drinking, a habit that continued in his later years. That was the only period in which Swami did figurative works, before moving on to the abstractions he became so well known for.

One of the highlights of the show is work from the "colour geometry" period with geometric shapes that are abstractions for homes or temples sitting on flat planes of colour. "He was inspired by Indian miniature painting but he took the figurative element out, " explains Kalidas.

Most of the works have a quiet serenity that belies Swami's rebellious nature. As a youth, he dropped out of his pre-medical course after realising that "I can draw a cockroach much better than dissect one".

He ran away to Calcutta to join the Congress Socialist Party. When he decided that it was losing direction, he joined the Communist Party of India in 1948 and was politically active. Aruna Asaf Ali, the Indian Independence activist, widely remembered for hoisting the Indian National Congress flag at the Gowalia Maidan in Bombay during the Quit India Movement, was one of his mentors and they read Marx together.

While he was addressing a political meeting in 1952, he spotted his wife Bhawani. They eloped and spent their honeymoon in a sanatorium in Betul in Madhya Pradesh. This was the artist's first encounter with tribal life that he was to paint years later.

In 1982, he went on to establish Bharat Bhawan which became a fulcrum of tribal and folk art and discovered the great Gond artist Jangarh Singh Shyam. But long before that, Swaminathan had been growing steadily disillusioned with communism. The Soviet Union's invasion of Hungary in 1956 sealed his disenchantment and he quit the party.

One of the things the fiery artist protested against was the Western influence on Indian art. Rebelling against the School of Paris style of modernism that he felt Progressives like Souza and Husain espoused, Swami went on to form Group 1890 in 1962. The name was deliberately meaningless (the number of the house the artists met in) and Swami wanted it so.

This show has a nice photograph of the artists in 1890 - Swami along with Jeram Patel, Himmat Shah, Jyoti Bhatt and G M Sheikh - against the backdrop of the Qutub Minar. The collective's manifesto rejected the "pastoral idealism of the Bengal School" and the "vulgar naturalism of Raja Ravi Varma".

The "stormy petrel" of modernism also had a caustic wit. In the draft of a letter to a newspaper, Swami argues for artiste status for circus clowns and simultaneously takes a dig at politicians saying "clowning has become almost a national pastime with politicians playing fast and loose with the lives of people".

Though the show is meant to be a slice from the early years, it does include some works he did in the early nineties. "Some of the early motifs return - squares, triangles, anthropomorphic birds, " says Kalidas. "It's almost as if he has come full circle. "

This isn't a retrospective though Gallery Espace, which has broken new ground with a non-commercial archival show, promises a full-fledged one.

'Transits of a Wholetimer' is on at Gallery Espace, Delhi, till October 6