At the onset of the South African War, Gandhi argued that Indians must support the war effort in order to legitimize their claims to full citizenship, organizing a volunteer ambulance corps of 300 free Indians and 800 indentured labourers called the Indian Ambulance Corps, one of the few medical units to serve wounded black South Africans. He himself was a stretcher-bearer at the Battle of Spion Kop, and was decorated. At the conclusion of the war, however, the situation for the Indians did not improve, but continued to deteriorate. In 1906, the Transvaal government promulgated a new Act compelling registration of the colony's Indian population. At a mass protest meeting held in Johannesburg on September 11th that year, Gandhi adopted his methodology of satyagraha (devotion to the truth), or non-violent protest, for the first time, calling on his fellow Indians to defy the new law and suffer the punishments for doing so, rather than resist through violent means. This plan was adopted, leading to a seven-year struggle in which thousands of Indians were jailed (including Gandhi himself on many occasions), flogged, or even shot, for striking, refusing to register, burning their registration cards, or engaging in other forms of non-violent resistance. While the government was successful in repressing the Indian protesters, the public outcry stemming from the harsh methods employed by the South African government in the face of peaceful Indian protesters finally forced South African General Jan Christiaan Smuts to negotiate a compromise with Gandhi.
It was the passage of the Asiatic Registration Act in Transvaal in 1907 which convinced Gandhi that the method of protest, petition and prayer which he had sedulously pursued for nearly fourteen years had failed. It was at this juncture that he evolved a new technique, which came to be known as Passive Resistance; but as it ruled out both verbal and physical violence, it differed in important respects from the campaign waged on behalf of the suffragettes in England. The principles and techniques of Gandhi’s movement were to evolve gradually in the ensuing months ant years; its author was a man for whom theory was the handmaid of action.