Oath of Allegiance (United Kingdom)
The Oath of Allegiance (also referred to as the Judicial Oath or Official Oath) is a pledge of loyalty to the reigning British monarch, their heirs, and successors, sworn by certain public servants in the United Kingdom, and by new citizens at British citizenship ceremonies. The current wording is prescribed by the Promissory Oaths Act 1868, with alternative solemn affirmations permitted under the Oaths Act 1978.
Source: Wikipedia — Oath of Allegiance (United Kingdom) (CC BY-SA 4.0)