He helped bring about India's independence from British rule, inspiring other colonial peoples to work for their own independence and ultimately dismantle the British Empire and replace it with the Commonwealth.
Gandhi's principle of satyagraha, often roughly translated as "way of truth" or "pursuit of truth," has inspired generations of democratic and anti-racist activists including Martin Luther King, Jr and Nelson Mandela.
He often stated his values were simple, drawn from traditional Hindu beliefs: truth (satya), and non-violence (ahimsa).
Mohandas Gandhi was born on October 2, 1869, in Porbandar, Gujarat, India. He was the son of a Karamchand Gandhi, the dewan (Chief Minister) of Porbander, and Putliba, Karamchand's fourth wife. They were descendents of traders (The word "Gandhi" means grocer). At the age of 13 Gandhi married Kasturbai, who was of his same age. They had four children, all sons: Harilal Gandhi born in 1888, Manilal Gandhi born in 1892, Ramdas Gandhi born in 1897 and Devdas Gandhi born in 1900.
At the age of 19, Gandhi went to University College, in the University of London to train as a lawyer. He went to Durban, South Africa to practice law in 1893 and began his political career by lobbying against laws discriminating against Indians in South Africa, inspired by an incident in which he was physically thrown off a train in Pietermaritzburg, after refusing to move to the third class coach, while travelling on a first class ticket.
Gandhi was arrested on November 6, 1913 while leading a march of Indian miners in South Africa.
Gandhi drew inspiration from the Bhagavad Gita and the writings of Leo Tolstoy, who in the 1880s had undergone a profound conversion to a personal form of Christian anarchism. Gandhi translated Tolstoy's "Letter to a Hindu"  which was written in 1908 in response to aggressive Indian nationalists, and the two corresponded until Tolstoy's death in 1910. The letter by Tolstoy uses Hindu philosophy taken from the Vedas and sayings of the Hindu God Lord Krishna to present his view of that state of growing Indian nationalism.
During World War I, Gandhi returned to India, where he campaigned for Indians to join the British Indian Army.
Gandhi's other successful strategies for the independence movement included swadeshi policy - the boycott of foreign-made goods, especially British goods. Linked to this was his advocacy that all Indians should wear khadi - homespun cloth, instead of relying on British-made textiles. Gandhi advocated that Indian women, rich or poor, should spend time each day spinning khadi in support of the independence movement. This was a strategy to include women in the independence movement at a time when many thought that such activities were not 'respectable' for women to engage in.
One of his most striking actions was the salt march known as the Dandi March, that started on March 12, 1930 and ended on April 5, when he led thousands of people to the sea to collect their own salt rather than pay the salt tax.
On May 8, 1933 Gandhi began a fast that would last 21 days to protest British 'oppression' in India.
In Bombay, on March 3, 1939 Gandhi fasted again in protest of the autocratic rule in India.
Gandhi became even more vocal in his demand for independence during World War II, drafting a resolution calling for the British to Quit India, which soon sparked the largest movement for Indian independence ever, with mass arrests and violence on an unprecedented scale. Gandhi and his supporters made clear that they would not support the war effort unless India was granted immediate independence. During this time, he even hinted an end for his otherwise unwavering support of non-violence, saying that the 'ordered anarchy' around him was 'worse than real anarchy'. He was then arrested in Bombay by British forces on August 9, 1942 and was held for two years.
Gandhi had great influence among the Hindu and Muslim communities of India.
It is said that he ended communal riots through his mere presence.
Gandhi was vehemently opposed to any plan which partitioned India into two separate countries (the plan was eventually adopted, creating a Hindu-dominated India, and a Muslim-dominated Pakistan).
On the day of the power transfer, Gandhi did not celebrate independence with the rest of India, but mourned partition alone in Calcutta instead.
He was assassinated in New Delhi on January 30, 1948 by Naturam Godse, a Hindu radical who held him responsible for weakening the new government by insisting on a payment to Pakistan. Godse was later tried, convicted, and executed.
It is indicative of Gandhi's long struggle and search for God that his dying words were a popular two-word mantra to the Hindu conception of God as Rama: "Hey Ram!" It is seen as an inspiring signal of his spirituality as well as his idealism regarding the possibility of unificatory peace. While there are some who are skeptical about this, the vast majority of evidence and witnesses, as well as popular opinion, seem to support this utterance as truly having occurred. #External links)
He was a strict vegetarian and had written books on the subject while studying law in London (where he met vegetarian campaigner Henry Salt at meetings of the Vegetarian Society). It might be added that the idea of vegetarianism was a deeply ingrained one in Hindu and Jain society in India, and that in his native land of Gujarat most Hindus were vegetarian. He experimented with different diets and believed that a diet should be enough to satisfy the minimum requirements of the body. He also abstained from taking food for periods of time, and he used this practice of fasting also as a political weapon.
Gandhi gave up sexual intercourse at the age of 36 and became totally celibate while still married, a course deeply influenced by the Hindu idea of brahmacharya, or spiritual and practical purity, largely associated with celibacy.
Gandhi spent a day of the week in silence. He would abstain from speaking and he believed it brought him inner peace. These were drawn from such Hindu understandings of the power of 'mouna' and 'shanti'. On such days he communicated with others by writing on paper.
After returning to India from a successful lawyer career in South Africa, he gave up his clothing that represented wealth and success. His idea was to adopt a kind of clothing whereby he can be accepted by even the poorest person in India. He advocated use of home-spun cloth (khadi). Gandhi and his followers followed the practice of weaving their own cloth using a spinning-wheel and wearing a dress made of that. He also advocated others use spinning wheels to spin clothes. This was a threat to the British establishment - while Indian workers were often idle due to unemployment, they bought their clothing from foreign English industrial manufacturers - if Indians spun their own clothes, this would leave British industry idle. The spinning wheel was later incorporated into the flag of the Indian National Congress.
Gandhi was against conventional education as taught in schools and believed that children learn best from parents and from the society. While in South Africa, Gandhi along with other elders formed a group of teachers and directly imparted education to the children.
M.K.Gandhi never received the Nobel Peace Prize, though he was nominated five times for the same between 1937 and 1948. Decades later however, the omission was publicly regretted by the Nobel Committee. When the Dalai Lama was awarded the Peace Prize in 1989, the chairman of the committee said that this was "in part a tribute to the memory of Mahatma Gandhi".
The official Nobel e-museum has an article discussing the issue.
Throughout his lifetime, Gandhi's activities attracted a wide range of comment and opinion. For example, as a subject of the British Empire, Winston Churchill once referred to Gandhi as a "brown fakir." Conversely, Albert Einstein said of Gandhi, "Generations to come, it may be, will scarcely believe that such a one as this ever in flesh and blood walked upon this earth."