One of only three British flags to survive the Battle of Trafalgar is at risk of the leaving the UK. Worn by RMS Royal Sovereign, the ship that led the British attack, it is the most historically significant of the three and the only complete example of a Union Jack from a 100-gun first-rate flagship. The Minister of Culture has placed a temporary export bar on the flag to give local institutions the chance to acquire it for the nation purchase price of 450,000 ($600,000) before it leaves the country.The Battle of Trafalgar took place on October 21, 1805, when the outnumbered British fleet under the command of then Vice-Admiral Horatio Nelson defeated the combined fleet of Napoleonic France and Spain. Commanded by Admiral Collingwood, Royal Sovereign led one of the two columns of warships with Admiral Horatio Nelsons Victory leading the other. Royal Sovereign moved faster under the days light winds than Victory and quickly pulled ahead of the other British ships, raking the Spanish three-decker ship Santa Ana. Royal Sovereign and Santa Ana fought each other for almost three hours until the latter surrendered. Royal Sovereigns foremast was heavily damaged, but the Union Jack was still flying.By the end of the battle, Royal Sovereign had lost her mizzen, mainmasts and foremast. The rigging was shot to tatters and the ship had to be towed. The flag bears the scars of its pole-position role in the fight. There are holes, burn marks, gunpowder stains and wooden splinters from the ship embedded in the woven cloth.Unique among the surviving Trafalgar flags, this one was made and repairs by the sailors of the Royal Sovereign. They made it from hand-stitched wool bunting with a weighted edge. Charles Aubrey Antram, one of Royal Sovereigns four masters mates kept it after the action, indicating he may have been the signal mate. It remained in his family by descent until 2004 when it was sold at auction to a private collector.Culture Minister, Baroness Twycross said:Few symbols in our country are as evocative as the Union Flag, and this flag in particular is an extraordinary representation of Britains history and national identity.This flag was made by ordinary Britons and now epitomises a defining moment in our national history. I hope this profoundly important historical artefact can remain in Britain for the public to enjoy.