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.
Jack (flag) Jack (flag) A jack is a national (originally naval) flag flown from a short jackstaff at the bow (front) of a vessel, while the ensign is flown on the stern (rear). Jacks on bowsprits or foremasts appeared in the 17th century. The word "jack" is said to result from the signature "Jacques" of King James I in whose reign (1603–1625) the Union Jack was designed. A country may have different jacks for different purposes, especially when (as in the United Kingdom and the Netherlands) the naval jack is forbidden to other vessels. The United Kingdom has an official civil jack;