The constitution of India imparts constitutional supremacy and not parliamentary supremacy as it is not created by the Parliament but created by a constituent assembly and adopted by its people with a declaration in the preamble to the constitution. Parliament cannot override the constitution.
The Constitution was adopted by the Constituent Assembly on 26 November 1949, and came into effect on 26 January 1950. The date of 26 January was chosen to commemorate the Purna Swaraj declaration of independence of 1930. With its adoption, the Union of India officially became the modern and contemporary Republic of India and it replaced the Government of India Act 1935 as the country's fundamental governing document. To ensure constitutional autochthony, the framers of constitution repealed the prior Acts of the British Parliament via the Article 395 of the constitution. India celebrates the coming into force of the constitution on 26 January each year as Republic Day.
The Constitution declares India a sovereign, socialist, secular, democratic republic, assuring its citizens of justice, equality, and liberty, and endeavours to promote fraternity among them.
The Constitution was drafted by the Constituent Assembly, which was elected by the elected members of the provincial assemblies. The 389 member Constituent Assembly took almost three years (two years, eleven months and eighteen days to be precise) to complete its historic task of drafting the Constitution for Independent India. During this period, it held eleven sessions covering a total of 165 days. Of these, 114 days were spent on the consideration of the Draft Constitution.