How did santhals lose their control over their own land?

Dear Student,
Following points will help you:

• Under British rule the functions and powers were taken from the tribal chiefs.
• The British through forest laws, restricted grazing , banned entry of villagers and tribes to reserved forests.  It lead to loss of customary rights.
• Changes in forest laws had a considerable effect on tribal lives. Forest were declared state's property by the Britishers. 

Thus, Santhals lost their control over their own land.