Events are due to take place to commemorate the centenary of the Gallipoli campaign, one of the bloodiest of World War One.
Prince Charles and Prince Harry will be among those attending services at the site of the battle at Cape Helles on the Turkish peninsula on Friday.
The leaders of Australia, New Zealand and Turkey will also attend the events.
About 141,000 died in the campaign, including 10,000 Australian and New Zealand Army Corps (Anzac) soldiers.
Allied forces landed on the Gallipoli peninsula in modern-day western Turkey – then part of the Ottoman Empire – in April 1915.
Their aim was to move inland and capture the capital Constantinople (now Istanbul) in order to force the Ottomans, who were fighting alongside the Germans, out of the war.
What was Gallipoli?
- The Allies and Germany had reached a stalemate on the Western Front just months into World War One
- Britain and France thought they could help Russia on the Eastern Front by defeating Germany’s Turkish allies – the Ottoman Empire
- After a failed naval attack, the Allies tried to capture Constantinople (now Istanbul) via the Gallipoli Peninsula by land assault
- British, French and their dominions’ troops took part including soldiers from Australia, New Zealand, India and Newfoundland
- They faced months of shelling, sniper fire and dysentery before abandoning the campaign
- 55,000 Allied troops died for no material gain, although the Turkish Army was tied down for eight months
- 86,000 Turkish troops died. Commander Mustafa Kemal survived and went on to found modern Turkey
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However, the invasion failed, with the Allied forces unable to advance more than a few kilometres inland.
A bloody stalemate ensued which lasted until Allied troops evacuated the peninsula eight months later in January 1916.
It was the first campaign that led to major casualties for Australian and New Zealand forces during World War One.
It also resulted in considerable losses for the Allied forces, including British, Irish, French, Indian, Gurkha and Newfoundland troops, as well as for the Turks.
A series of events to mark the 100th anniversary of the landings will begin on Friday, with a Commonwealth and Irish commemoration.
Warships from Allied nations will fire a salute in honour of the sailors who died.
The Gallipoli campaign
350,000 British troops, 35,000 died
79,000 French troops, 10,000 died
74,000 Anzac troops, 10,000 died
400,000 Turkish troops, 86,000 died
Prince Charles and Prince Harry will lay wreaths, before meeting descendants of veterans who fought at Gallipoli on board the Royal Navy’s flagship, HMS Bulwark.
There will also be an international ceremony organised by Turkey and a service to mark France’s participation in the battle.
On Saturday, there will be services to to mark Anzac Day, which is widely marked in Australia and New Zealand.
Why do Australians and New Zealanders mark Anzac Day?
- Gallipoli was the first campaign Australia and New Zealand fought as independent nations
- They joined the Allies in an attempt to knock Germany’s Turkish allies out of World War One
- But the Allies faced months of shelling, sniper fire and dysentery. The Anzacs barely advanced a mile inland
- 10,000 Anzacs died while 23,000 were injured, which had a devastating impact on the male population of the fledgling nations
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The centenary is expected to be the largest ever commemoration of the battle, with Turkish President Tayyip Erdogan, Australian Prime Minister Tony Abbott, New Zealand Prime Minister John Key and Prince Charles leading the ceremonies.
Thousands of Australians, New Zealanders and Turks are also expected to make the journey to Gallipoli for the anniversary, including relatives of those who fought and died at Gallipoli. There are no longer any surviving veterans of the campaign.
In London, The Queen, the Duke of Edinburgh, who is Patron of the Gallipoli Association, and Prince William will be joined by senior government and military figures to lay wreaths at the Cenotaph in Whitehall.