This was made easier as Pakistan was a member of the Commonwealth.
The majority are Sunni Muslims, with a significant minority of Shia Muslims.
Most returned to the South Asia after their service, although many of these former soldiers returned to Britain in the 1950s and 1960s to fill labour shortages.
Following the Second World War, the break-up of the British Empire and the independence of Pakistan, Pakistani immigration to the United Kingdom increased, especially during the 1950s and 1960s.
At 19, Jinnah became the youngest person from South Asia to be called to the bar in Britain.
Most early Pakistani settlers (then part of the British India Empire) and their families moved from port towns to the Midlands, as Britain declared war on Germany in 1939.
The UK also has one of the largest overseas Christian Pakistani communities; the 2011 census recorded around 17,000 Christian Pakistanis living in England and Wales.