In 1890, Tilak became a member of the Indian National Congress. He was opposed to its moderate stance, especially in the battle for self-government. At the moment, he was one of the most prominent revolutionaries.
The bubonic plague spread from Bombay to Pune in late 1896, and by January 1897, it had reached epidemic proportions.
Forced entry into private homes, an inspection of residents, relocation to hospitals and segregated camps, removal and destruction of personal belongings, and prohibiting patients from entering or leaving the city were among the harsh steps used to deal with the emergency.
The outbreak had been brought under control by the end of May. They were generally seen as acts of injustice and dictatorship.
Tilak took up the cause by publishing provocative articles in his newspaper Kesari, citing the Hindu scripture Bhagavad Gita to claim that no one should be held responsible for killing an oppressor without expecting a reward.
The Chapekar brothers and their associates then shot and killed Commissioner Rand and another British officer, Lt. Ayerst, on June 22, 1897.
Tilak was charged with murder incitement and received an 18-month sentence. He was respected as a martyr and a national hero when he was released from jail in modern-day Mumbai.
After this, he declared "Swaraj is my birthright, and I shall have it."
Tilak encouraged the Swadeshi and Boycott movements after the Partition of Bengal, which was a policy devised by Lord Curzon in order to undermine the nationalist movement.
The boycott of foreign products, as well as a social boycott of every Indian who used foreign goods, were also part of the campaign.
Swadeshi was a movement that promoted the use of locally made products. When foreign products were boycotted, a void had to be filled by domestic demand.
Swadeshi and Boycott campaigns, according to Tilak, are two sides of the same coin.
Tilak opposed Gopal Krishna Gokhale's moderate views and was backed by fellow Indian nationalists such as Bipin Chandra Pal in Bengal and Lala Lajpat Rai in Punjab. The "Lal-Bal-Pal triumvirate" was their nickname.
The Congress Party's annual meeting was held in Surat, Gujarat, in 1907. The selection of the new president of Congress sparked a battle between the party's moderate and extreme wings.
The party was divided into two factions: the extremists and the moderates. The extremists were led by Tilak, Pal, and Lajpat Rai. Tilak was supported by nationalists such as Aurobindo Ghose and V. O. Chidambaram Pillai.
Tilak was tried for sedition three times by the British India Government during his lifetime, among other political cases, in 1897, 1909, and 1916.
Tilak was sentenced to 18 months in prison in 1897 for preaching anti-Raj discontent.
He was charged with sedition and inflaming ethnic tensions between Indians and the British again in 1909.
In Tilak's defence, Bombay lawyer Muhammad Ali Jinnah appeared, but he was sentenced to six years in prison in Burma in a contentious ruling.
When Tilak was charged with sedition for the third time in 1916 over his self-rule lectures, Jinnah was his counsel again, and this time he was acquitted.
When World War I broke out in August 1914, Tilak notified King-Emperor George V of his support and used his oratory to recruit new soldiers for the war effort.
He applauded the British Parliament's passage of the Indian Councils Act, also known as the Minto-Morley Reforms, in May 1909, describing it as "a significant increase in trust between the Rulers and the Ruled."
During the Lucknow Pact of 1916, Tilak reunited with his fellow nationalists and rejoined the Indian National Congress.
Tilak tried to persuade Mahatma Gandhi to abandon the concept of total nonviolence in favour of achieving Swarajya by any means necessary.
Though Gandhi disagreed with Tilak on the methods for achieving self-rule and was a staunch supporter of satyagraha, he admired Tilak's contributions to the nation and his courage of conviction.
After Tilak lost a civil suit against Valentine Chirol and suffered financial loss, Gandhi urged Indians to donate to the Tilak Purse Fund, which was established to cover Tilak's expenses.
Bal Gangadhar Tilak, along with G. S. Khaparde and Annie Besant, helped found the All India Home Rule League in 1916–18.
He gave up after years of trying to get the moderate and conservative groups together and concentrated on the Home Rule League, which advocated for self-rule.
Tilak went from village to village seeking help from farmers and locals to join the self-rule movement.
In April 1916, the league had 1400 members, and by 1917, it had risen to about 32,000.