What is the official flag of the United Kingdom?

The flag of the United Kingdom, often called the Union Jack or Union Flag, is a powerful symbol of the country's history and unity. It's a combination of three older flags: the red cross of St. George, representing England; the white saltire of St. Andrew, representing Scotland; and the red saltire of St. Patrick, representing Northern Ireland. The flag’s design reflects the Act of Union in 1801, which formally united Great Britain and Ireland (though the current flag only represents Northern Ireland after the Republic of Ireland became independent). So, while the Commonwealth is an association of nations with historical ties to the UK, and British Knights certainly had shields, and trade unions are important for workers' rights, neither of those are the official flag. The Union Jack is the specific banner that represents the United Kingdom as a nation, and it’s flown on government buildings, used in official ceremonies, and recognized worldwide as the emblem of the UK.