Mizoram was carved out of Assam as a Union Territory in 1972.
By 1987, it became a full-fledged state.
The two states have sparred over this 164.6 km long inter-state border over the past, sometimes leading to violent clashes.
The dispute stems from two notifications passed under British era.
First, notification of 1875 that differentiated Lushai Hills from the plains of Cachar.
Second, notification of 1933 that demarcates a boundary between Lushai Hills and Manipur.
Mizoram claims that the land is theirs is based on an 1875 notification, which came from the Bengal Eastern Frontier Regulation Act of 1873.
Assam for its part, claims that the land is theirs.
It goes by a 1933 notification by the state government that demarcated the Lushai Hills, which Mizoram was formerly known as, from the province of Manipur.
During colonial times, Mizoram was known as Lushai Hills, a district of Assam.