France, UK mark centenary of Somme battle 8 days after Brexit vote

Ceremonies to mark the centenary of World War I's Battle of the Somme began at 7.28am local time at the site in northern France on Friday, while Queen Elizabeth II laid flowers at the tomb of the unknown soldier in London's Westminster Abbey. With the ceremonies coming eight days after Britain voted to leave the EU, French President François Hollande commented that the "European idea" had brought 70 years of peace to the continent.

British soldier at the Thiepval memorial to mark the 100th anniversary of the Battle of the Somme Reuters/Phil Noble

At a vigil in France the Duke of Cambridge paid tribute to the fallen soldiers saying "we lost the flower of a generation".

Hollande joined Prince William and his wife, Kate Middleton, for a two-minute silence to mark the start of the battle at the Lochnagar Crater (the Trou de la Mine in French), where British and French troops set off 30 tonnes of explosives under the German defences, starting the battle.

The 91-metre diamater crater is still visible today.

Later in the day Prince Charles, the heir to the British throne, was to be present at the ceremony at the Thiepval memorial, which some 12,000 people were expected to attend.

British Prime Minister David Cameron and the British royals were to read writings of former soldiers, while Hollande was to read an extract from Georges Duhamel's Civilisation, which record the horrors of the war.

The day will end with a ceremony at the Fricourt cemetery, where 17,027 German soldiers are buried.

Over a million killed and wounded

An estimated 1,200,000 soldiers were killed, wounded or went missing - 500,000 of them British, 200,000 French - at

the Battle of the Somme, making it the "most deadly of the Great War", according to the ceremonies' organisers.

The British and French armies fought the Germans for five months in a battle of attrition along a 15-mile front.

Brexit casts its shadow

Although Hollande's advisers told Le Monde newspaper he was anxious to show that Brexit "take nothing away from our friendship and everything the British have done for Europe", the French president did make a point of praising the "European idea" on Thursday evening.

It has "allowed us to overcome divisions and rivalries between states and brought us peace for 70 years", he commented.