The British wanted the peasants to pay compensation because they demanded 15% of the landholding and the entire Indigo harvest. Let's examine this answer in detail:

1. The Background:
During the British rule in India, the cultivation of Indigo became an important cash crop for the British East India Company. Indigo was used to produce a blue dye that was in high demand in Europe. The British landlords in Bengal, Bihar, and Orissa forced the local peasants to cultivate indigo on a large scale.

2. Indentured Labor:
The cultivation of indigo required a significant amount of labor. The British landlords used a system known as the "Tinkathia" or "Batai" system, which forced the peasants to cultivate indigo on a portion of their land. The peasants were then obligated to deliver the entire indigo harvest to the British landlords.

3. The Demand for Compensation:
As the British rule in India started to weaken, the peasants began to resist the forced cultivation of indigo. They demanded their freedom from this oppressive system and refused to pay compensation to the British landlords.

4. The British Response:
In response to the peasant rebellion, the British implemented various measures to suppress the resistance. One such measure was the demand for compensation. The British landlords insisted that the peasants should pay 15% of their landholding and the entire indigo harvest as compensation for their alleged breach of contract.

5. Reasons for Compensation:
The British justified the demand for compensation by claiming that the peasants had signed contracts agreeing to cultivate indigo. They argued that the peasants were obligated to fulfill their contractual obligations, and failure to do so required them to pay compensation.

6. Economic Exploitation:
The demand for compensation was primarily a means for the British to continue exploiting the peasants economically. By forcing the peasants to pay compensation, the British landlords ensured that they could extract as much profit as possible from the indigo cultivation, even in the face of resistance.

In conclusion, the British demanded compensation from the peasants as a means to maintain their economic control and exploit the indigo cultivation system. The demand for 15% of landholding and the entire indigo harvest was a way to ensure that the British landlords could continue profiting from the labor of the peasants, even as the British rule in India was coming to an end.