In the 17th century, Queen Elizabeth issued a royal charter establishing the British East India Company (EIC) to trade in the East Indies. Because the Dutch already had a stronghold on the Spice Islands (consisting of the Moluccas and Bandas), the EIC turned its attention toward India's textiles, spices and opium. However, India was far from unified at this time: It was comprised of individual territories controlled by different rulers. The EIC brokered contracts with these rulers and gradually gained influence over the subcontinent.
As the EIC increased its administrative and political power in India, conditions between the Indians and their European colonizers became more hostile. The company was able to quell Indian rebellions in the 18th century, but in 1857, Indian members of the EIC militia revolted, marking the beginning of the Sepoy Rebellion, or Indian War of Independence.
After two years, the British finally succeeded in putting down this bloody rebellion. But as a result, the British government dissolved the EIC and opted for direct rule of India. Direct British rule became known as the Raj. Needless to say, this development didn't squelch the desire for self-government. In 1885, the Indian National Congress (INC) formed to promote Indian involvement in the government.
By 1919, after Indians helped the British in World War I, the INC focused on attaining complete independence. It was then that Gandhi emerged. The philosophy he developed that encouraged fighting evil with peace is known as satyagraha. Under this ethos, one achieves profound insight into absolute truth by embracing nonviolence and self-scrutiny.
Those who practice satyagraha must never act in secrecy -- they must make their plans and intentions known. This explains why Gandhi wrote an open letter to Lord Irwin, the viceroy of India, requesting an end to the salt tax and explaining his intentions before setting out on a 240-mile (386.2-kilometer) trek to protest the tax. Irwin could've easily arrested Gandhi. But Gandhi was an important public figure, and Irwin knew that arresting him would spark intense backlash [source: Martin]. Instead, Irwin simply replied that he regretted Gandhi would be breaking the law and endangering public peace [source: Moraes].
With that, the salt march was set in motion.