Flag of Great Britain
| King's Colour | |
| Use | Civil and state flag |
|---|---|
| Proportion | 3:5 |
| Adopted |
|
| Relinquished | 1801 |
| Design | Four stripes of white, (horizontal, vertical and two diagonal) on a blue field, with a central red cross; all extend to edge |
| Red Ensign of Great Britain | |
| Use | Civil and naval ensign |
| Design | A red field with the flag of Great Britain in the canton |
| Blue Ensign of Great Britain | |
| Use | Civil and naval ensign |
| Design | A blue field with the flag of Great Britain in the canton |
| White Ensign of Great Britain | |
| Use | Naval ensign |
| Design | A cross of St George with the flag of Great Britain in the canton |
The flag of Great Britain, often referred to as the King's Colour, Union Flag, Union Jack, and British flag (retroactively prefixed as being the "first" such flag, in order to distinguish it from the modern flag of the United Kingdom), was used at sea from 1606 then more generally from 1707 until 1801 as the flag of the Kingdom of Great Britain, and is the precursor to the modern Union Jack.
Set down in 1606 by Royal decree of James VI and I, the flag's form combined the flag of the Kingdom of England and flag of the Kingdom of Scotland and was specifically intended for maritime use by vessels of both kingdoms, which since 1603 had shared a single monarch in a personal union following the Union of the Crowns. In 1634, Charles I proclaimed that the flag's use be restricted to vessels of the Navy Royal and Royal Scots Navy, stating that it "be reserved as an ornament proper for Our own Ships and Ships in our immediate Service and Pay, and none other".
The flag was subsequently adopted as the national flag of the unified Kingdom of Great Britain, following the Acts of Union 1707; gaining the status of "the Ensign armorial of the Kingdom of Great Britain". It was later adopted by land forces; however, the shade of blue of land-based versions appears on contemporary works of art to have been lighter than those intended for maritime use; darker dyes being used at sea for durability.
The flag of Great Britain consists of two Christian crosses; the flag consists of the red cross of Saint George, patron saint of England, superimposed on the white saltire of Saint Andrew, patron saint of Scotland. Its correct proportions are 3:5. The blue field on the flag was sky blue at first; however, over time darker shades of blue were employed to counter the effects of weathering at sea.
With few exceptions, the flag's official use came to an end in 1801, following the Acts of Union 1800 and the creation of the United Kingdom of Great Britain and Ireland whereby the Saint Patrick's Cross, representing the Kingdom of Ireland, was added to the flag of Great Britain to create the flag of the United Kingdom.