In India, a set of recently discovered photographs is drawing attention to the role of women in one of the country's biggest anti-colonial movements, known as the civil disobedience movement, led by Mahatma Gandhi in 1930-31.

The images do not simply capture female participation. They are visual proof of how women commanded and dominated political activity, often relegating men to the sidelines.

In April 1930, Gandhi concluded his pivotal salt march, breaking the British monopoly on salt production - a charged symbol of colonial misrule. Raising a handful of muddy salt from the sea, he declared himself to be "shaking the foundations of the British Empire".

Afterwards, Gandhi presided over waves of civil disobedience protests, encouraging supporters of the Indian National Congress to manufacture contraband salt, boycott foreign goods, and face down phalanxes of lathi-wielding policemen. Just a few months before, the Congress had declared purna swaraj (complete independence) as its political objective for India.

Historians have long recognised the civil disobedience movement as an important turning point in Indian politics.

First, women joined anti-colonial activities in greater numbers. When Gandhi began his salt march he forbade women from joining, but several female leaders eventually convinced him to accord them a greater role.

Second, Congress leaders harnessed modern media technologies like radio, film, and photography, which helped their political struggle reach an international audience.

About 20 years ago, one album of photographs from the movement appeared at a London auction. Tipped off by an antiquarian dealer in Mumbai (formerly Bombay), the Alkazi Foundation, a Delhi-based art collection, acquired the album.

Small in size with a coal-gray cover, the album gave few clues about its provenance.

Scrawled on its spine were the words "Collections of Photographs of Old Congress Party- K. L. Nursey."

No one knew the identity of KL Nursey. Typewritten photo captions were brief and rife with spelling and factual errors. The album remained undisturbed in the Alkazi Foundation's collections until its curator and two historians from Duke University began to reexamine it in 2019.

They were shocked by what they found.

Despite their unknown origins, the photographs of the Nursey album told a dramatic and detailed story.

Pictured here were the streets of Bombay, tense and bristling with thousands of volunteers aligned with the Congress. Unlike earlier photographs of political activity in India, these are not posed-for images: they capture violent confrontations with police, wounded volunteers loaded onto ambulances, boisterous marches amidst monsoonal downpours, and endless streams of protesting men and women through Bombay's Indo-Gothic streetscape. There is an electric energy running through the black-and-white images.

Above all, the album brings to light, perhaps better than any other source, how women used the civil disobedience movement for their empowerment.

"We were immediately struck by the emphasis on women in action," says Sumathi Ramaswamy of Duke University, who, along with her colleague Avrati Bhatnagar led the detailed examination of the album.

In one picture, Lilavati Munshi, an intrepid Congress leader from Gujarat, instructs a group of men raiding a government-owned salt pan. In another, Munshi stands defiantly before the entrance of a boycotted British department store, uncowed by a group of British police officers towering over her - and stylishly dressed in a sleeveless sari blouse.

This visual record of female leadership is unique. Despite its leftward leanings and Gandhi's prodding, Indian nationalist activity had remained an overwhelmingly male endeavour, with its own distinct patriarchal flavor.

As recently as the noncooperation movement in 1920-22, women played a far more circumscribed role. Now, however, women's involvement took a quantum leap.

Beyond recognisable figures like Munshi, the Nursey album documents thousands of completely unknown female volunteers.

Women gather on the shores of Bombay's Chowpatty Beach, ready to make contraband salt. Members of the Desh Sevika, an all-female volunteer force, wrestle with police attempting to snatch away their provisional national flag. Perhaps most striking of all was how many female volunteers brought along their young daughters, inducting new generations of women into anticolonial politics.

The Nursey album also points to remarkable inversions of gender dynamics.

Long processions of women, many of them bearing a takli or spindle to honour Gandhi's commitment to homespun khadi cloth, take over Bombay's streets, quite literally pushing men to the very margins. Elsewhere, middle-class men, many of whom had rarely set foot inside a kitchen, hold impromptu classes where they instruct volunteers on boiling and cooking salt.

It is these nameless men and women who help us better understand this chapter of India's history. "We associate the civil disobedience movement with Gandhi," Ms Ramaswamy says. "But when we began studying the album, we were soon convinced that it made a different argument: that the people of Bombay made the movement that in turn made Gandhi globally famous."

Here, the camera played a critical role. In ways that could not be captured in written sources, photographs demonstrate women taking nationalist activities into their own hands: challenging policemen, drumming up support for boycotts, addressing crowds, directing salt production, and courting arrest.

"Participation in the nationalist movement was not only a catalyst for the political awakening of Indian women," Ms Bhatnagar says. "It also created new possibilities for them to step into public roles and occupy civic spaces in ways that had rarely been seen before."

Many of the photographed women look directly at the camera, conscious of their political activity being documented for posterity. In this way, Ms Bhatnagar continues, "they claimed freedom from colonial rule but also from prevailing gendered division of spaces, between the domestic and the public".

The Nursey album is also a stunning testament to the urban transformation of Bombay.

Below the domes and spires of a colonial metropolis, a discernible transfer of power is evident, as khadi-clad Congress volunteers outnumber pith-helmeted policemen and army soldiers. They commandeer the city's most prominent landmarks, rallying outside Victoria Terminus (today's Chhatrapati Shivaji Maharaj Terminus) and climbing onto the neoclassical Fitzgerald Fountain at Dhobi Talao. Colonial authorities, meanwhile, transform the Worli chawls - tenement housing for cotton mill workers - into makeshift prisons for detained nationalists.

"Though photography already had a century-long history in Bombay, political activism was captured by the lens for the first time in the Nursey album," says Murali Ranganathan, a historian of Bombay.

These photographs in the Nursey album are now back in public circulation.

Ramaswamy and Bhatnagar recently released a book titled, Photographing Civil Disobedience, which includes many of the images alongside articles by a number of scholars. In October, they opened two museum exhibits, both titled Disobedient Subjects, at the CSMVS Museum in Mumbai and Duke's Center for Documentary Studies.

The women volunteers of the civil disobedience movement are getting a belated acknowledgement of their defining role in one of India's biggest mass movements.

Nearly a century later, their resolve and determination are as palpable as they were when first captured on camera.