Union Jack
![The Union Flag: a red cross over combined red and white saltires, all with white borders, over a dark blue background.](/Images/godic/202502/02/Flag_of_the_United_Kingdom.svg3831.png")
![The Union Jack flying beside Saint George's Cross](/Images/godic/202502/02/Union_Flag_and_St_Georges_Cross3831.jpg")
![HMS Cornwall,](/Images/godic/202502/02/HMS_Cornwall_F99_July_20063832.jpg")
![Development of the Union Jack.](/Images/godic/202502/02/Flags_of_the_Union_Jack3832.png")
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, by law, an official flag in Canada 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 Jack also appears in the canton (upper left-hand quarter) of the flags of several nations and territories that are former British possessions or dominions.