The national flag of the United Kingdom is the Union Jack, also known as the Union Flag. The design of the Union Jack dates back to the Act of Union 1801 which united the Kingdom of Great Britain and the Kingdom of Ireland (previously in personal union) to create the United Kingdom of Great Britain and Ireland. The flag consists of the red cross of Saint George (patron saint of England (which also represents Wales)), edged in white, superimposed on the saltire of St Patrick (patron saint of Ireland), also edged in white, which are superimposed on the saltire of Saint Andrew (patron saint of Scotland). Wales is not represented in the Union Flag by Wales's patron saint, Saint David, because the flag was designed whilst Wales was part of the Kingdom of England. (Source: Wikipedia.org, CC BY-SA)