The tens of thousands of soldiers who gave their lives on the first day of the Battle of the Somme have been honoured with a two-minute silence as commemorations get under way in the UK and France.
Prince William and his brother Prince Harry led tributes to thousands of British soldiers who died at a memorial service on Thursday on the eve before the 100th anniversary of the start of the battle.
As dawn broke on 1 July, 1916, there was a momentary silence before the whistles blew and thousands of men rose from their muddy trenches and climbed over the top to walk slowly towards the enemy’s front line.
Mr Cameron has said the 100-year commemoration allows people to “reflect on the sacrifice not just of the thousands of British and Commonwealth troops who gave their lives, but of the men on all sides who did not return home.”