Union Jack Flag - Official Flag of the United Kingdom #3586516 (License: Personal Use)

The Union Jack is the de facto national flag of the United Kingdom, composed of three heraldic crosses: the red cross of St George (England), the white diagonal cross of St Andrew (Scotland), and the red diagonal cross of St Patrick (Northern Ireland). Its distinctive red, white, and navy blue colors are precisely proportioned, with the flag flown both horizontally and vertically (with the broader white stripe above the red in the upper-left canton when hoisted correctly). The design has remained unchanged since 1801, following the Acts of Union with Ireland.

This image is commonly used on government websites, educational resources, travel guides, and news articles about the UK. It serves users seeking visual identification of British identity, historical context, or official representation-especially around national events like Trooping the Colour, royal occasions, or international diplomacy.