The principle of single citizenship in India was taken from England. This concept is based on the idea that a person can have only one citizenship at a time, and that the rights and privileges of that citizenship are determined by the country of origin. Here are some details about how this principle was adopted in India:

Adoption of Single Citizenship Principle:
India adopted the principle of single citizenship when it became a republic in 1950. Prior to this, the country had been governed under the British Indian Act of 1935, which recognized dual citizenship for Indians. However, with the adoption of the new Constitution, India became a sovereign, democratic republic with a single citizenship for all citizens.

Features of Single Citizenship in India:
Some of the key features of the single citizenship principle in India include:

1. All citizens of India are entitled to the same rights and privileges, regardless of their state or region of origin.

2. The Constitution of India guarantees fundamental rights and freedoms to all citizens, regardless of their religion, caste, or gender.

3. The Indian Constitution provides for a federal system of government, with powers divided between the central government and the states. However, the principle of single citizenship ensures that all citizens have equal rights and protections under the law, regardless of the level of government they are dealing with.

4. The principle of single citizenship has helped to promote national unity and integration in India by emphasizing that all citizens are equal under the law, regardless of their background or identity.

Conclusion:
In conclusion, the principle of single citizenship in India was taken from England and has been an important feature of the country's democratic system since its adoption in 1950. By providing equal rights and protections to all citizens, regardless of their region or identity, this principle has helped to promote national unity and integration in India.