British India got its independence in 1947 and was split into 5 states:
- India
- Ceylon (Sri Lanka)
- Burma (Myanmar)
- Pakistan - West and East Pakistan - actually split on either side of India which was a bit awkward, the latter became Bangladesh eventually.
- Jammu and Kashmir
The Maharaja of J&K (a Hindu) originally chose to be independent because he would have joined India, but the population being primarily muslim was a bit of a pickle. Pakistan was pissed off, attempted to invade and the Maharaja of J&K asked India for help, which they agreed to on the condition that his state would be joining the Indian dominion.
It's been a shitshow ever since.