Sultan Kwaje’s problems started when his country disappeared from under him. He was born in the southern part of Sudan but has lived in the north for more than three decades. When South Sudan broke away as an independent country from Sudan in July, Kwaje was left on the northern side of the border, a foreigner. The Sudanese government, he said, fired him from his job in the civil service. Tens of thousands of South Sudanese in the north lost their jobs after the split. About 500,000 are now technically illegal because they lack official residency papers.
Link to Reuters website: In Sudan and South Sudan, questions of nationality