12 April: On this day in history

Three years after James VI of Scotland headed south to take the English throne, the king and his advisers contemplated a question that would have enormously long-lasting consequences. Although the two kingdoms remained separate jurisdictions, should their ships fly the same flag?

The issue might seem academic, but after reports of altercations between English and Scottish ships, the king was keen to find a symbol of harmony. For months his courtiers discussed various designs, and at last, in the spring of 1606, they came up with a winner.

On 12 April, then, James issued a proclamation, “declaring what Flags South and North Britons shall bear at Sea”. It was evident, he said, that “some difference has arisen between our Subjects of South and North Britain, Travelling by Sea, about the bearing of their flags”. So “henceforth all our subjects of this Isle and Kingdom of Great Britain” should fly from the maintop “the Red Cross, commonly called St George’s Cross, and the White Cross, commonly called St Andrew’s Cross, joined together”.

The exact original design is now lost, but it was probably very similar to the flag generally flown before 1801, when it was adapted to include the cross of St Patrick. And to settle a hoary old question: was it the union flag, or the union jack? The answer is simple. For the first few years, at least, nobody called it either. | Written by Dominic Sandbrook

12 April 1709

The first edition of Tatler is published. The thrice-weekly paper is produced by London Gazette editor Richard Steele under the nom de plume of Isaac Bickerstaff Esq.

12 April 1917

Canadian troops complete the capture of Vimy Ridge.

12 April 1853

Birth of cardiologist James Mackenzie. He was regarded as the world’s leading clinical authority on the heart and in 1913 was appointed physician in charge of the Uk’s first cardiac department at the London Hospital.

12 April 1861

Confederate forces began the bombardment of Fort Sumter at Charleston, South Carolina. Although shots had been fired before this, the episode effectively marked the start of the American Civil War.

12 April 1912

Teacher and nurse Clarissa 'Clara' Barton died in Maryland, aged 90. Barton was founder and first president of the American Red Cross, which held its first meeting in her Washington apartment in May 1881

12 April 1988

Harvard College is issued the first patent for a new animal life form – a genetically-altered mouse developed by Philip Leder and Timothy Stewart.

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