The revolutionary activity in the Punjab-United Provinces-Bihar region during the 1920s was spearheaded by the Hindustan Republican Association (HRA), later renamed the Hindustan Socialist Republican Association (HSRA). Here's a breakdown of key events and developments:

1. Formation of HRA: Founded in October 1924 in Kanpur by Ramprasad Bismil, Jogesh Chandra Chatterjee, and Sachin Sanyal, the HRA aimed to organize an armed revolution to overthrow British colonial rule and establish a Federal Republic of United States of India based on adult franchise.
2. Kakori Robbery (August 1925): The HRA carried out the Kakori robbery, holding up the 8-Down train at Kakori and looting its official railway cash. This action led to a government crackdown, resulting in arrests, trials, and the execution of several HRA members, including Ramprasad Bismil.
3. Formation of HSRA: In September 1928, the HRA was reorganized as the Hindustan Socialist Republican Association (HSRA) at a meeting in the ruins of Ferozshah Kotla in Delhi. Under the leadership of Chandra Shekhar Azad, the HSRA adopted socialism as its official goal and decided to work under a collective leadership.
4. Saunders' Murder (Lahore, December 1928): Bhagat Singh, Azad, and Rajguru assassinated J.P. Saunders, a police official responsible for the lathi-charge on an anti-Simon Commission procession, to avenge the death of Lala Lajpat Rai. This act of individual assassination marked a shift in strategy for the HSRA.
5. Bomb in the Central Legislative Assembly (April 1929): Bhagat Singh and Batukeshwar Dutt threw bombs in the Central Legislative Assembly to protest against the passage of the Public Safety Bill. The bombs were deliberately made harmless to avoid casualties but aimed at drawing attention to the revolutionary cause.
6. Trials and Protests: Bhagat Singh, Sukhdev, and Rajguru were tried in the Lahore conspiracy case, while other revolutionaries faced trials in various other cases. In jail, they protested against inhumane conditions through fasting. Jatin Das became the first martyr after a 64-day fast.
7. Continued Struggle: Despite the executions of Bhagat Singh, Sukhdev, and Rajguru in March 1931, revolutionary activities continued in Punjab and the United Provinces throughout 1930, with numerous violent incidents.
8. Azad's Death: Chandra Shekhar Azad died in a police encounter in Allahabad in February 1931, while attempting to evade arrest.

These events highlight the determination and sacrifice of the revolutionaries in their struggle against British colonial rule, inspiring generations of Indians in the fight for independence.

The revolutionary activity in Bengal during the 1920s and 1930s saw the reorganization of underground groups and their collaboration with the Congress. Here's a summary of the key events and aspects:

1. Reorganization of Revolutionary Groups: Many revolutionary groups reorganized their activities underground, while others continued to work within the Congress, aligning with leaders like C.R. Das. After Das's death in 1925, the Bengal Congress split into factions led by J.M. Sengupta and Subhash Bose, with the Anushilan and Yugantar groups respectively backing them.
2. Government Crackdown: The government cracked down heavily on revolutionaries, leading to arrests and executions. Gopinath Saha's attempted assassination of Calcutta Police Commissioner Charles Tegart in 1924 resulted in severe repression, including the execution of Saha.
3. Chittagong Armoury Raid (April 1930): Led by Surya Sen, the Chittagong group carried out a successful raid on two main armouries in Chittagong. The raid aimed to seize arms, disrupt communication lines, and challenge British authority. Despite Sen's subsequent arrest and execution in 1934, the raid inspired many youth to join the revolutionary cause.
4. Participation of Women: The revolutionary movement saw significant participation from young women, particularly under Surya Sen's leadership. Women like Pritilata Waddedar, Kalpana Dutt, Santi Ghosh, Suniti Chandheri, and Bina Das played active roles in sheltering revolutionaries, carrying messages, and engaging in armed resistance.
5. Emphasis on Group Action: There was a shift towards group action targeting colonial institutions rather than individual acts. The objective was to set an example for the youth and undermine colonial authority.
6. Inclusivity: The movement shed some conservative elements and religious rituals, facilitating the participation of Muslims. Surya Sen's group included Muslims, fostering a more inclusive approach.
7. Drawbacks: Despite its strengths, the movement retained some conservative elements and failed to evolve broader socio-economic goals. Additionally, collaboration with Swarajists did not adequately address the concerns of Muslim peasants against zamindars in Bengal.

Overall, the revolutionary movement in Bengal during this period was characterized by determined resistance against colonial rule, significant participation from women, and a shift towards group action and inclusivity. However, it faced challenges and limitations in achieving broader socio-economic objectives and addressing the needs of marginalized communities.
The official reaction to the revolutionary activities during the 1920s was characterized by panic followed by severe government repression. The government responded with the implementation of 20 repressive Acts, unleashing the police on the revolutionaries. In Chittagong, villages were burned, and punitive fines were imposed on many others. Additionally, Jawaharlal Nehru was arrested for sedition in 1933 and sentenced to two years in prison for condemning imperialism and praising the heroism of the revolutionaries.

However, amidst the government repression, a significant ideological rethinking occurred among revolutionaries, particularly spearheaded by Bhagat Singh and his comrades. This ideological evolution began in the mid-1920s when the Hindustan Republican Association (HRA) decided to preach revolutionary and communist principles. The HRA manifesto declared its stance against systems enabling exploitation and advocated for the nationalization of key industries and transport systems. By the late 1920s, the revolutionaries moved away from individual heroic actions towards mass politics, promoting Hindu-Muslim unity and advocating for equal rights over natural resources.

Bhagat Singh, in particular, shifted his focus from violent and individual heroic action to Marxism, emphasizing the importance of a popular, broad-based movement for a successful revolution. He played a key role in establishing organizations like the Punjab Naujawan Bharat Sabha and the Lahore Students' Union for open, legal work among youth, peasants, and workers. Bhagat Singh and his comrades realized the necessity of organizing and developing a mass movement among the exploited and suppressed sections of society.

However, despite this shift towards mass politics, there was still a perceived need for individual heroic action among some revolutionaries. This was partly due to the slow process of ideological change and the challenge of mobilizing people quickly. Some believed in the efficacy of "propaganda by deed," utilizing individual actions and court proceedings as a means of revolutionary propaganda.

Bhagat Singh's perspective on revolution marked a departure from traditional notions of militancy and violence. He redefined revolution as a means to achieve national liberation and to usher in a new socialist order aimed at ending exploitation. Here are the key points of his ideology:

1. Non-Violent Conception of Revolution: Bhagat Singh emphasized that revolution did not necessarily involve violent struggle or personal vendettas. Instead, it aimed to address manifest injustice and bring about fundamental changes in the existing order.
2. Acceptance of Marxism and Class Approach: Bhagat Singh embraced Marxist ideology and the class approach to society. He recognized the need for peasants to liberate themselves not only from foreign rule but also from the exploitation by landlords and capitalists. He viewed socialism as the scientific abolition of capitalism and class domination.
3. Secularism and Tolerance: Bhagat Singh advocated for secularism and tolerance in society. He believed in the importance of separating religion from politics and promoting a general sense of tolerance among people. He emphasized the need to free individuals from the mental bondage of religion and superstition.
4. Importance of Moral Strength and Critical Thinking: Bhagat Singh stressed the importance of moral strength, criticism, and independent thinking in revolutionary activism. He believed that revolutionaries needed to possess not only moral courage but also the ability to question and think critically.

Overall, Bhagat Singh's ideology encompassed a holistic vision of revolution that aimed not only for political liberation but also for social and economic justice, secularism, and intellectual freedom.