Nelson Mandela was tried for treason due to his involvement in the anti-apartheid movement in South Africa. The trial lasted from 1956 to 1961 and had a significant impact on the course of Mandela's life and the struggle against racial segregation in the country.

Background of Apartheid:
Apartheid was a system of racial segregation enforced by the National Party government in South Africa from 1948 to 1994. It aimed to institutionalize the supremacy of the white minority over the non-white majority population, comprising mainly black Africans.

Mandela's Role in the Anti-Apartheid Movement:
Nelson Mandela, a lawyer and member of the African National Congress (ANC), played a crucial role in opposing and fighting against apartheid. He was a vocal advocate of non-violent resistance, but as the government cracked down on peaceful protests, he became convinced that armed struggle was necessary to end apartheid.

The Treason Trial:
1. The Beginnings:
In 1952, Mandela and other ANC leaders were arrested for organizing a campaign of civil disobedience against apartheid laws. The charges were later dropped, but the government closely monitored Mandela's activities.

2. The Arrests:
In December 1956, Mandela was arrested along with 155 other activists and charged with treason. The government accused them of planning to overthrow the state through acts of sabotage and violence.

3. The Trial:
The trial began in 1956 and lasted for five years. Mandela, along with his co-defendants, faced the death penalty if found guilty. The defense argued that their actions were in response to the unjust laws of apartheid, and they had no intention to overthrow the government.

4. Acquittal and Impact:
In 1961, after a lengthy trial, Mandela and his co-accused were acquitted of treason. However, the government continued to crack down on anti-apartheid activists, leading Mandela to go underground and eventually form the armed wing of the ANC, known as Umkhonto we Sizwe.

Significance of the Trial:
1. Publicity and International Attention:
The treason trial brought international attention to the struggle against apartheid, raising awareness about the oppressive regime in South Africa.

2. Mandela's Transformation:
During the trial, Mandela's views shifted towards armed struggle, setting the stage for his future involvement in the armed resistance against apartheid.

3. Unity and Resilience:
The trial also fostered a sense of unity among anti-apartheid activists and showcased their resilience in the face of government repression.

Conclusion:
Nelson Mandela's trial for treason was a pivotal moment in his life and the anti-apartheid movement. It not only highlighted the injustice of apartheid but also contributed to Mandela's transformation and the eventual downfall of the apartheid regime.