Pre-independence scenario 

The British colonial government policies brought forward the elements of regionalism in 3 different stages: 

1. The development process of British India was around the three large provinces of Bengal, Bombay and Madras. Afterwards, they started integrating other regions under these provinces. 
2. For better administration, the British government initiated the process of bifurcation of large states on communal lines. This led to unconscious arousal of separate identity. Assam was the first state to witness this.  
3. Last stage was when they used a policy of "divide and rule" to maintain control over India and exploit the differences between different regions and communities.  

Here are some of the ways in which the British government brought regionalism to India during colonial rule: 

• Administrative Reforms: The British colonial government introduced administrative reforms that created administrative divisions based on linguistic, cultural, and religious differences. This led to the formation of provinces and regions based on language, such as the formation of the Bengal Presidency in 1765, which included the present-day states of West Bengal, Bihar, and Odisha. 
• Census and Surveys: The British colonial government conducted census and surveys that classified the Indian population based on linguistic, religious, and ethnic differences. This led to the creation of ethnolinguistic maps of India, which further reinforced regional identities. 
• Communal Award: In 1932, the British colonial government introduced the Communal Award, which granted separate electorates to different religious and caste groups. This policy further strengthened communal identities and created the basis for the formation of regional political parties. 
• Language Policy: The British colonial government introduced a language policy that promoted English as the official language of the country, which created resentment among the Indian people who spoke different languages. This led to the demand for recognition and promotion of regional languages, which further reinforced regional identities. 

Post-Independence Scenario 

Indian leaders made concerted efforts to integrate Indian citizens by promoting the idea of a united India that transcended regional, linguistic, and religious differences. Indian leaders, such as Mahatma Gandhi, Jawaharlal Nehru, and Sardar Vallabhbhai Patel, promoted the idea of Indian nationalism, which emphasized a common national identity that transcended regional and religious differences. They believed that a strong sense of nationalism was essential for the country's unity and development.