The flag of the United Kingdom combines the cross of St. George (a red cross on a white background) with the cross of St. Andrew. This combination of the 2 crosses was made in 1801 after the union between England and Scotland. It forms the flag that we know today and that we call "Union Jack.
However, the British ships that sail the oceans do not carry this flag at their stern. They fly the Red Ensign, a red flag with the Union Jack in one corner. But curiously, this flag is often on a red background, but sometimes with blue or even white. Where does this change come from and what do these colors mean?
The Red Ensign, the most popular
Since 1864, the Red Ensign has been used to signal English merchant ships, and by declination pleasure craft. It is therefore the most common flag worn by the British.
The Blue Ensign
The Blue Ensign is reserved for public service ships or ships commanded by a reservist officer of the Royal Navy (England's maritime armed force). Thus, this particular flag can be found on English merchant ships whose command and crew include a certain number of retired or reservists from the Royal Navy. More anecdotally, yachts belonging to members of certain old English clubs, for example the Royal Northern & Clyde Yacht Club are allowed to fly this flag.
The White Ensign
The White Ensign (also known as Saint George's Ensign) is the flag of the British military (the Royal Navy). It is worn on Royal Navy ships and at Royal Navy operated bases. The Royal Yacht Squadron and the ships accompanying the Queen also fly it.
A small logo on the Red Ensign
Sometimes the Red Ensign has an extra small design in the red part. These are the flags of Guernsey, Isle of Man or Bermuda.
