Kashmir is an area in Asia that is not controlled by a single government.
It is in an area of the world that used to be controlled by the British government, in a time when Pakistan didn't even exist as a country.
In 1947 Britain gave up its control of the area, and two separate countries were created - India and Pakistan.
India is mainly a country where Hindus live, most Pakistanis are Muslims.
The area we now call Kashmir was a princely state whose leader at the time wanted it be a country of its own.
In October 1947, a few months after Britain withdrew, Pashtun tribesmen invaded Kashmir from Pakistan. Some people think they were supported by the Pakistani government.
The leader of Kashmir then asked India for some soldiers to help make his state safe, who sent a military force into the area to help.
Pakistan and India then began fighting over the state, and when the violence stopped the line between the two forces became a border, called the line of control.
Since then India and Pakistan have both tried to take control of Kashmir, until a war in 1971 ended with each of them taking charge of a separate chunk of the area.
Even since that agreement Pakistan and India still both want complete control of Kashmir, and the area has seen lots of violence.