Denization is an obsolete or defunct process in England and Ireland and the later Kingdom of Great Britain, the United Kingdom, and the British Empire, dating back to the 13th century, by which an alien (foreigner), through letters patent, became a denizen, thereby obtaining certain rights otherwise normally enjoyed only by the King's (or Queen's) subjects, including the right to hold land.
While one could become a subject via naturalisation, this required a private act of Parliament (or latterly of a colonial legislature); in contrast, denization was cheaper, quicker, and simpler.
"[3] The denizen had limited political rights: he could vote, but could not be a member of parliament or hold any civil or military office of trust.
[1] Denizenship has also been compared to the Roman civitas sine suffragio, although the rights of denizens were restricted by the Act of Settlement 1701, not by common or immemorial law.
[7] The British Nationality Act 1948, a major reform of citizenship law in Britain, made no mention of denization and neither abolished nor preserved the practice.