Step 1: State when and where:
The Santhal rebellion (Santhal Hul) broke out in 1855-56 in the Rajmahal Hills region of the Santhal Parganas (present-day Jharkhand, then part of Bengal Presidency).
Step 2: State the leadership:
It was led by the Murmu brothers -- Sidhu and Kanhu Murmu -- along with their brothers Chand and Bhairav, against British rule, zamindars and moneylenders (mahajans).
Final Answer:
\[ \boxed{\text{1855-56, Rajmahal Hills/Santhal Parganas; led by Sidhu and Kanhu Murmu}} \]