Explanation:

 The most effective tribal movement of this period was, however, the Santhal hool (rebellion) of 1855-56. The Santhals lived scattered in various districts of Curtack, Dhalbhum, Manbhum, Barabhum, Chota Nagpur, Palamau, Hazaribagh, Midnapur, Bankura and Birbhum in eastern India. Driven from their homeland, they cleared the area around the Rajmahal Hills and called it Damin-i-koh. They were gradually driven to a desperate situation as tribal lands were leased out to non-Santhal zamindars and moneylenders. To this was added the oppression of the local police and the European officers engaged in railroad construction. This penetration of outsiders called dikus by the Santhals-completely destroyed their familiar world, and forced them into action to take possession of their lost territory. In July 1855, when their ultimatum to the zamindars and the government went unheeded, several thousand Santhals, armed with bows and arrows, started an open insurrection "against the unholy trinity of their oppressors-the zamindars, the mahajans and the government". The insurrection spread rapidly and in a wide region between Bhagalpur and Rajmahal the Company's rule virtually collapsed, spreading panic in government circles. At this stage the Santhal rebels were also being actively helped by the low caste non-tribal peasants. This invited brutal counter-insurgency measures; the army was mobilised and Santhal villages were burnt one after another with vengeance. According to one calculation, out of thirty to fifty thousand rebels, fifteen to twenty thousand were killed before the insurrection was finally suppressed. Henceforth, the British government became more cautious about them and the Santhal inhabited areas were constituted into a separate administrative unit, called the Santhal Parganas, which recognised the distinctiveness of their tribal culture and identity.
Some Major Tribal Movements in India 15.5.1 Tamar Revolts (1789-1832) 15.5.2 The Kherwar Movement of the Santhals (1833) 15.5.3 Santhal Revolt of 1855 15.5.4 Bokta Rising, Sardari Larai or Mukti Larai Movement of 1858-95 153.5 Birsa Munda Revolt (1895-1901) 15.5.6 Devi Movement in Gujarat (1922-23) 15.5.7 Tribal Movement in Midnapur (1918-1924) 15.5.8 Jitu Santhal's Movement in Malda (1924-32) 15.5.9 Tribals and National Movement in Orissa (1921-36) -15.5.10 Tribal Movement in Assam (the then Assam, Nagaland, Meghalaya and 'Mizoram)