The UK issued a new 12-sided £1 coin into circulation.
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The strain of swine flu known as H1N1 had its first case in the US.
Roman Emperor Valentinian I made his brother, Flavius Valens, his co-emperor.
The Treaty of Florence was signed, which ended the war between the French Republic and the Kingdom of Naples.
The world's largest dinosaur footprint was discovered.
Frenchman Henri Fabre flew the world's first seaplane in Martinique, France.
