Punjab, Pakistan
The major and native language spoken in the Punjab is Punjabi (which is written in a Shahmukhi script in Pakistan) and Punjabis comprise the largest ethnic group in country. Punjabi is the provincial language of Punjab, but is not given any official recognition in the Constitution of Pakistan at the national level.
History of East Pakistan
One of the most divisive issues confronting Pakistan in its infancy was the question of what the official language of the new state was to be. Mohammad Ali Jinnah yielded to the demands of refugees from the Indian states of Bihar and Uttar Pradesh, who insisted that Urdu be Pakistan's official language. Speakers of the languages of West Pakistan (Punjabi, Sindhi, Pushtu, and Baluchi) were upset that their languages were given second-class status. In East Pakistan, the dissatisfaction quickly turned to violence. The Bengalis of East Pakistan constituted a majority (an estimated 54%) of Pakistan's entire population. Their language, Bengali, like Urdu, belongs to the Indo-Aryan language family, but the two languages have different scripts and literary traditions.