Descendants of the Battle of Somme have come together at Edinburgh Castle to mark the 100th anniversary of Britain's bloodiest battle.

The Somme was the largest western front battle of the First World War, beginning on July 1 1916 and ending 141 days later on November 18.

More than one million men were wounded or killed, 420,000 of them from the British Army.

Battle of the Somme Vigil chairman Major General Mark Strudwick CBE, whose grandfather fought in the battle, said: "It was a hugely important battle that highlighted the courage and commitment of those brave British soldiers who volunteered and went into battle where they had no idea what they would be facing.

"They had to actually defend our line and they had to break through the German line, otherwise the war was lost.

"If it was lost, then we wouldn't have an independent country now, we wouldn't have other independent countries in Europe."

An overnight vigil will be held on June 30 at the Scottish National War Memorial, organised in partnership with WW100 Scotland, Royal British Legion Scotland, the Ministry of Defence, Historic Environment Scotland and the Royal Edinburgh Military Tattoo.

The memorial will be open between 6.45pm and 8.30pm for the public to pay respects to those who fell.

It will be one of four national commemorative events taking place across the four nations of the UK.

Alan Hamilton, 64, chair of the Royal Army Service Corps and one of the sentinels at the vigil, will blow a whistle to mark the end of the two-minute silence which belonged to his great-uncle Robert who fought in the battle, one hundred years to the minute that he blew it on July 1 1916 as he led his troops into battle.

He said: "At 7.30 in the morning of the 1st of July 2016, I will be blowing the same whistle to mark the end and to commemorate the fallen.

"I think it's fantastic to say that this whistle has got 100 years of history already and, with a bit of luck, it will continue to have another 100 years of history."

51 Scottish battalions took part in the campaign at the Somme, including the renowned 16th Battalion Royal Scots, "McCrae's Battalion", which was largely made up of professional and amateur sportsmen and their supporters.

Speaking at the event and representing the Royal Regiment of Scotland, Major William Wright said: "When you consider why young men lost their lives during that period so that we can actually live the lives we live today, that's got to be keenly felt."

Members of the public wishing to attend the memorial can apply for one of four separate time slots beginning between 6:45pm and 8:15pm online at Eventbrite or by calling the ticket hotline on 0300 244 4000.

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