Conversation so far:
what was pakistan called before it was pakistan
In the Partition of India, British India was divided into two independent dominion states, the Union of India and the Dominion of Pakistan
when was pakistan established
The modern state of Pakistan was established on 14 August 1947
how many wings did pakistan consist of in 1947
From 1947 to 1971 newly independent Pakistan comprised two wings, the eastern and the western.

Question: when did the east become independent
Self-contained rewrite: when did east pakistan become independent