Somme 100

At 07.30 on 1 July 1916, whistles were blown up and down the British front line and thousands of men climbed from their trenches into no man's land - it was the first day of the Battle of the Somme.

To mark this moment 100 years on, Huw Edwards and Dan Snow in Thiepval, France, Sonali Shah in Sheffield Memorial Park, France, and Kirsty Young in Westminster Abbey, London, will present a special live broadcast on BBC One. The Kings Troop Royal Horse Artillery will fire their guns on Parliament Square and two minutes' silence will be observed.

Then, at 9.15am on BBC One, Huw Edwards will introduce live coverage of the centenary Somme commemoration at the Thiepval Memorial, France, to remember the one million casualties sustained on both sides during the 141 days of the battle. One hundred years on from the first day of this defining World War One battle, TRH The Prince of Wales and Duchess of Cornwall, TRH The Duke and Duchess of Cambridge and HRH Prince Henry of Wales will join heads of state and 10,000 spectators. The Thiepval Memorial stands in commemoration to the missing of the Somme, the 72,000 men that have no known grave. Sonali will be speaking to those taking part in services in Sheffield Memorial Park in northern France.