​London is the capital and largest city of England and the United Kingdom. 8.63 million people live in London, which is on the River Thames.

London is the biggest city in western Europe, and the world's largest financial centre.

London was founded by the Romans in Londinium. London is also known as Lunnainn in Scottish Gaelic, Llundain in Welsh and Londain in Irish.

For a long time, London was a small city. All its people lived inside the walls that were built by the Romans. This area is still called the City of London. There were many villages around the city. Gradually, more people came to live there. Then, step by step, the villages joined together into one huge city.

​The Union Jack, or Union Flag, is the national flag of the United Kingdom of Great Britain and Northern Ireland. The flag also has an official or semi-official status in some other Commonwealth realms.

The Union Jack also appears in the canton (upper left-hand quarter) of the flags of several nations and territories that are former British possessions or dominions.

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The claim that the term Union Jack properly refers only to naval usage has been disputed, following historical investigations by the Flag Institute in 2013.