The public trust doctrine asserts that certain natural resources, such as air, water, and forests, are meant for public use and cannot be privately owned. Originating from the teachings of Byzantine Emperor Justinian I and later adopted by English law and the Indian Constitution, it obligates the government to protect these resources for the benefit of all citizens. Landmark Indian Supreme Court cases illustrate the doctrine's application in safeguarding environmental rights and navigating the balance between development and ecological preservation.