The Green Ensign is an historic flag flown by some Irish merchant vessels from the 17th Century to the early 20th Century. The flag consists of a green field with a golden harp and a canton containing either the English Flag (St George's cross) or a version of the Union Flag (pre 1800 - a combination of St George's cross and St Andrew's cross, post 1800 - containing the addition of St Patrick's cross). The existence of this flag has been disputed although it has appeared in the following historical flag plates: The tricolor flag of France A flag is a piece of coloured cloth flown from a pole or mast, usually for purposes of signalling or identification. ... Cargo ship or freighter is any sort of ship that carries goods and materials from one port to another. ... (16th century - 17th century - 18th century - more centuries) As a means of recording the passage of time, the 17th century was that century which lasted from 1601-1700. ... (19th century - 20th century - 21st century - more centuries) Decades: 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s As a means of recording the passage of time, the 20th century was that century which lasted from 1901–2000 in the sense of the Gregorian calendar (1900–1999 in the... St Georges cross The St Georges cross, a red cross on a white background, is the national flag of England and was adopted for the uniform of English soldiers during the military expeditions by European powers to recapture the Holy Land from Muslims (Crusades of the 11th, 12th... Flag Ratio: 1:2 The Union Flag or Union Jack is the flag most commonly associated with the United Kingdom of Great Britain and Northern Ireland and was also used throughout the former British Empire. ... 1800 was a common year starting on Wednesday (see link for calendar). ...

 1685 Downham's Flag Chart 1700 Len's Flag Chart 1799 Flags of all Nations 1848 Flaggen Aller Seefahrenden Nationen 1889 Drawings of Flags of All Nations - British Admiralty 1917 National Geographic Flag Book 

There remains a lively debate concerning whether the flag had any form of official status within the British Isles or was simply an informal flag used by some merchant ships.