Names Union Jack, Union Flag, other names: The Britain ; The British Flag ; the Union ; The Banner of the Union ; the Great Union ; the Flag of the Union ; the Jack ; The King's Jack ; His Majesty’s Jack ; Our Jack ; the Jack Flag Use National flag Proportion 3:5 (on land) 1:2 (at sea) Adopted 1 January 1801; 223 years ago (1801-01-01 ) first design: 12 April 1606; 417 years ago (1606-04-12 ) Design A combination of the crosses of SS Andrew, George, and Patrick Variant flag of the United Kingdom of Great Britain and Northern Ireland
Use Civil ensign Proportion 1:2 Design A red flag with the Union Flag in the corner at the top of the flag pole. See Red Ensign . Variant flag of the United Kingdom of Great Britain and Northern Ireland
Use Civil air ensign Proportion 1:2 Design A blue flag with the Union Flag in the corner at the top of the flag pole and a black cross in the centre. See Civil Air Ensign . Variant flag of the United Kingdom of Great Britain and Northern Ireland
Use State ensign Proportion 1:2 Design A blue flag with the Union Flag in the corner at the top of the flag pole. See Blue Ensign . Variant flag of the United Kingdom of Great Britain and Northern Ireland
Use Naval ensign Proportion 1:2 Design A white flag with the Union Flag in the corner at the top of the flag pole and a red cross in the centre. See White Ensign . Variant flag of the United Kingdom of Great Britain and Northern Ireland
Use Air force ensign Proportion 1:2 Design A blue flag with the Union Flag in the corner at the top of the flag pole and the RAF roundel on the opposite side.