The Era of Militant Nationalism (1905-1919) 

Cause of its growth, exposition of the nature of British rule:

The Moderates like Dadabhai Naoroji, M.G. Ranade, R.C. Dutta etc. exposed in their writings, the nature of economic exploitation of the Indian mass by the British authority.
The apathetic attitude of the British Government towards the people who came under the gap of terrible famines between 1896 and 1900 discharged venom in the minds of Indians towards the British rule. Any progressive attitudes of the Indians were opposed by the British authorities. This was very well noticed by the leaders of Indian National Congress and prepared the way for the rise of extremism.
Racial antagonism:
The Britishers always projected before the Indian people their racial superiority. Their wrong deeds were even supported by the Anglo-Indian newspapers. Nobody could raise finger towards the actions of the British authority. They dealt with the Indians mercilessly who prayed for justice.
In every action, right or wrong, the Britishers justified their stand. The vernacular press reflected all these inhuman, undemocratic and brutal works of the Britishers that contributed a lot for the rise of militant nationalism.
Result of the social and cultural awakening:
The nineteenth century Renaissance reformed Indian society and contributed for the advancement of the culture of this land. It created a sense of self-respect among the people of India. The proud Indians now forgot their inferiority complex and came forward to challenge western culture and administration and thus, emerged the leaders like Bal Gangadhar Tikal, Lala Lajpat Rai, Begin Chandra Pal and others to have a. deal with the British Government.
The ideology of Moderates no more acceptable:
The emerging leaders within the Indian National Congress became grossly dissatisfied with the 'prayer and petition' technique of the Moderates and their liberal outlook towards the British rule. They viewed that the Moderates would fail to achieve the goal what the Indians wanted. Aurobindo Ghosh's article 'New Lamps in place of Old Lamps' in the magazine Indus Prakash was pointer in this direction.
Lajpat Rai viewed the annual sessions of the Indian National Congress as 'annual national festivals of the educated Indians'. Similar opinions were formed by the younger generation represented by Tikal, D. H. Chapeau, Lala Mushy Ram etc. who challenged the leadership of the Moderates,
Unemployment:
The British authority could not generate employment facilities to the educated Indians. Further, the Indians, who were in service, were low-paid. They came forward and joined hands with the militant nationalists preaching against the colonial rule of the British people.
International events:
Certain international events during that time influenced the course of Indian history. Abyssinia defeated Italy in 1896. In 1905 Russia was defeated by Japan, Egypt, Ireland, Turkey and Persia demanded self-government. This showed that even small country could challenge the mighty power and that gave rise to extremism in Indian politics.
The reactionary policies of British Viceroys:
The Viceroys of British India opened their Pandora’s Box to suppress the Indians. Bal Gangadhar Tikal organized the peasants in Maharashtra and advised them not to pay revenue to the government due to failure of crops. He was arrested in 1897 and thrown inside the jail for eighteen months. The Chapeau brothers were sentenced to death for murdering two plague officers. The Nat brothers were banished from country due to the charge of treason. Lord Curzon marched ahead with his programme of centralization of administration by passing Indian Universities Act and Calcutta Corporation Act. He also followed the principle 'Divide and rule' by creating communalism among the Hindus and Muslims.
Partition of Bengal:
Lord Curzon's partition of Bengal in 1905 brought division among the Hindus and Muslims. Bengal was dominated with Hindu population and the new provinces of eastern Bengal and Assam constituted with the dominance of Muslim population. Surrender Nath Banerjee took the lead in opposing the partition and maintaining friendly ties among the Hindus and Muslims. This partition Of Bengal infuriated the Indians and led to the rise of extremism.
The leadership of Lal-Bal-Pal and Aurobindo:
Lala Lajpat Rai, Begin Chandra Pal, Bal Gangadhar Tikal and Aurobindo Ghosh gave direction to the national movement. They opposed the repressive policies of the government with boldness, courage and self-confidence. Their leadership gave new dimension to the Indian politics. People ungrudgingly accepted their leadership and followed them in perpetuating extremism.