Union Jack Union Jack The Union Jack, or Union Flag, is the national flag of the United Kingdom. The flag also has an official or semi-official status in some other Commonwealth realms: for example, it is a ceremonial flag in Canada by parliamentary resolution, and known there as the Royal Union Flag. Further, it is used as an official flag in some of the smaller British overseas territories. The Union Flag also appears in the canton (upper left-hand quarter) of the flags of several nations and territories that are former British possessions or dominions, as well as the state flag of Hawaii.
Union Jack (Royal Navy), the Red ensign (Merchant and private boats) or the Blue ensign (government departments and public corporations). Similar ensigns are used by other countries (such as New Zealand and Australia) with the Union Flag in the canton. Other Commonwealth countries (such as India and Jamaica) may follow similar ensign etiquette as the UK, replacing the Union Flag with their own national flag. The flag in a white border occasionally seen on merchant ships was sometimes referred to as the Pilot Jack. It can be traced back to 1823 when it was created as a signal flag, never intended as