Monday 4 August marks the 100th anniversary of Great Britain declaring war on Germany. The First World War, also known as the Great War, lasted until 11 November 1918 and is recognised as one of the deadliest historical conflicts with millions of casualties.

The area around the strategic Belgian town of Ypres saw some of the heaviest and most prolonged fighting. The total Allied and German casualties in the five Battles of Ypres is thought to exceed 850,000.

Getty Images photographer Christopher Furlong visited these Flanders fields on the centenary of WWI.

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A preserved WWI trench system is pictured in Sanctuary Wood in Ypres.Getty
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Bomb craters scar the woodland floor in the preserved Sanctuary Wood.Getty
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Damaged helmets, recovered shells and munitions sit on display at Sanctuary Wood.Getty
A surviving tree, damaged in the Great War, is covered in tributes.Getty
The remains of a World War One stretcher is seen among recovered artefacts at the preserved Sanctuary Wood.Getty
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The morning sun falls on the fortified Advanced Dressing Station, near Essex Farm Cemetery in Ypres, where Canadian doctor Lieutenant Colonel John McCrae treated the wounded and is believed to have composed his famous poem 'In Flanders Fields' after burying his friend, Lieutenant Alexis Helmer, on 3 May 1915.Getty
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Wild poppies grow on the verge of a Flanders field near Passchendaele as dawn breaks on the centenary of the Great War.Getty
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The setting sun creates long shadows at Sanctuary Wood Military Cemetery in Ypres.Getty

Ypres was the centre of five battles between German and Allied forces from 1914 to 1918. The deadliest of these was the Third Battle of Ypres or the Battle of Passchendaele, between July and November 1917.

Casualty numbers are disputed, but it is thought that around 325,000 Allied and 260,000 German troops lost their lives.

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5 January 1917: Soldiers march past the ruins of St Martins Church and Cloth Hall in Ypres.Getty
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5 October 1917: Australian troops march towards the front line to relieve their comrades, who had won Broodseinde Ridge the previous day, during the Battle of Passchendaele.Getty
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11 November 1917: Soldiers pose for a photo near the ramparts at Ypres the day after British, Canadian, ANZAC, and French forces finally recaptured the Passchendaele Ridge east of Ypres.Getty
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19 April 1918: Soldiers lie dead in the mud on a battlefield during the Lys Offensive, also known as the Fourth Battle of Ypres.Getty