Comprehensive regulation of immigration is a modern area of law, which grew particularly during the late 20th century as ordinary people became more globally mobile, and the United Kingdom became an increasingly attractive place to live and work.
The original inhabitants of the British Isles are thought to be Celtic, though for centuries people from surrounding countries had come to settle.
Moreover, the British Nationality Act 1772 allowed people to be considered English if their father was, although born abroad.
The Aliens Act 1905 required registration and placed general controls under the authority of the Home Secretary.
The overwhelming majority of new citizens come from Asia (40%) and Africa (32%), the largest three groups being people from Pakistan, India and Somalia.