In 1947, one million Muslim Biharis migrated from India, like so many others, to Pakistan – East Pakistan. Educated and fluent in Urdu, the Biharis were treated as part of the elite, filling major bureaucratic and private-sector positions, all the while remaining separate from the 'local' population. As a result, the Bangla-speaking populace grew resentful, viewing these migrants as supporters and symbols of unjust West Pakistani domination. The Biharis drew even more Bangladeshi ire during the liberation war of 1970-71. Since the group regarded itself as Pakistani, the majority sided with West Pakistan, some joining the armed movements.
After India's intervention in December 1971, Pakistan evacuated Bangladesh. Left behind, in a country that had formed around them, were over one million Urdu-speaking Biharis. Persecuted, their property and houses seized, their jobs terminated, by 1972 1,008,680 Biharis were interned in camps across Bangladesh.
While these 'temporary' camps were being constructed, officials from Pakistan, Bangladesh and the international community committed themselves to finding a solution. Of these three, the first agreed to repatriate the Biharis, the second to tolerate them for the time being, and the third to support them. The agreement is now decades old, but Islamabad accepted only a few of those it had promised to repatriate, while Dhaka let them sink to the absolute margins of society. The international community turned its attention to new challenges, and the Biharis became stateless.
And there, in the camps, the Biharis remain. Over half (600,000) accepted Bangladesh's offer of citizenship in 1974, while 539,000 registered with the International Community of the Red Cross as refugees, to "return to their country of nationality – Pakistan". Since 1972, Pakistan has accepted back around 175,000 Biharis. 300,000, meanwhile, have continued to live in the camps for more than three decades.