Introduction
The landmark case that brought the Basic Structure Doctrine into the limelight is the Kesavananda Bharati case (1973). This case is considered one of the most significant constitutional cases in Indian history.

Background
The Basic Structure Doctrine refers to the idea that there are certain fundamental features of the Constitution that cannot be amended by the Parliament. These features form the basic structure of the Constitution and are essential for upholding the principles of democracy, federalism, secularism, and rule of law.

Kesavananda Bharati Case
The Kesavananda Bharati case was brought before the Supreme Court of India in 1973. It challenged the constitutional validity of the 24th Amendment Act, which sought to curtail the power of the judiciary and give the Parliament the authority to amend any part of the Constitution, including the fundamental rights.

Arguments
The petitioner, Kesavananda Bharati, argued that the Parliament's power to amend the Constitution should not extend to altering its basic structure, as it would undermine the principles of democratic governance and violate the fundamental rights of the citizens. The Attorney General, on behalf of the government, argued that the Parliament should have the authority to amend any part of the Constitution, including the basic structure.

Judgment
In a historic judgment, the Supreme Court, by a narrow margin of 7-6, held that while the Parliament has the power to amend the Constitution, it cannot alter its basic structure. The Court recognized the basic structure as an essential feature of the Constitution that cannot be abrogated.

Impact
The Kesavananda Bharati case laid down the foundation for the Basic Structure Doctrine, which has since become an integral part of Indian constitutional law. This doctrine acts as a safeguard against arbitrary amendments to the Constitution and protects the fundamental principles enshrined in it. It ensures that the basic structure of the Constitution, including principles of democracy, federalism, secularism, and fundamental rights, remains intact and unalterable.

Conclusion
The Kesavananda Bharati case was a landmark moment in Indian constitutional history. It established the Basic Structure Doctrine, which has played a crucial role in upholding the principles of democracy, federalism, and fundamental rights. The judgment in this case reaffirmed the supremacy of the Constitution and the role of the judiciary in safeguarding its basic structure.