The parents of Jack Letts, dubbed Jihadi Jack, say the UK government is "shirking responsibility".Read more
In 2009 all retired Gurkhas were finally allowed to settle in the UK.
Bumi Thomas, a jazz artist who thought she was a British citizen, is now facing deportation from the UK.
An Indian army veteran tells the BBC about his arrest after his citizenship was questioned.
In 1929, an African-American Ford engineer, Robert Robinson, was recruited to work in the USSR. He had to stay there, against his will, for nearly 50 years.
What Brexit, freedom of movement and citizenship mean to three people living in Berlin.