The Non-Cooperation Movement of 1920 was a significant milestone in India's struggle for independence from British colonial rule. It was a mass protest campaign led by Mahatma Gandhi and the Indian National Congress (INC) with the aim of achieving self-governance and ending British domination in India. The movement was triggered by a series of events and circumstances that had a profound impact on the Indian people.

1. Jallianwala Bagh Massacre:
- The Jallianwala Bagh Massacre, which took place on April 13, 1919, was a turning point in India's fight for freedom.
- British troops under the command of General Dyer opened fire on a peaceful gathering of Indians who were protesting against the repressive Rowlatt Act.
- This brutal act resulted in the loss of hundreds of innocent lives and deeply angered the Indian population.

2. Rowlatt Act:
- The Rowlatt Act was passed by the British government in 1919, giving extensive powers to the colonial government to arrest and detain Indians without trial.
- The act was seen as a direct attack on civil liberties and was met with widespread opposition from Indians who felt it violated their rights.

3. Khilafat Movement:
- The Khilafat Movement was launched by Indian Muslims to protest against the dismantling of the Ottoman Caliphate by the British after World War I.
- The movement gained support from Mahatma Gandhi and the INC, who saw it as an opportunity to unite Hindus and Muslims in the fight against British imperialism.
- However, when the British failed to address the demands of the Khilafat leaders, disillusionment set in, and the movement merged with the larger non-cooperation movement.

4. Influence of Mahatma Gandhi:
- Mahatma Gandhi played a pivotal role in mobilizing the masses and channeling their discontent into a nonviolent protest movement.
- His philosophy of nonviolence (Ahimsa) and civil disobedience resonated with the Indian people, who were inspired by his leadership and principles.
- Gandhi called for a boycott of British goods, schools, courts, and government institutions, urging Indians to assert their own self-reliance and independence.

5. Widespread discontent among Indians:
- The economic hardships faced by Indians, coupled with the discriminatory policies of the colonial government, had created widespread discontent among the masses.
- Peasants, workers, students, and intellectuals were all affected by British policies, and they saw the non-cooperation movement as a means to express their grievances and assert their rights.

In conclusion, the Non-Cooperation Movement of 1920 was a response to the oppressive British rule and the events that had deeply affected the Indian population. The Jallianwala Bagh Massacre, the Rowlatt Act, the Khilafat Movement, the influence of Mahatma Gandhi, and widespread discontent among Indians all contributed to the circumstances that led to the non-cooperation movement. It marked a turning point in India's struggle for independence and brought the issue of self-governance to the forefront of the national consciousness.