French President Francois Hollande (R) walks followed by Britain's Prince William (2ndL), his wife Catherine, the Duchess of Cambridge (L) and Britain's Prince Harry (3rdL) during a memorial ceremony the memorial ceremony at the Franco-British National Memorial in Thiepval near Albert, during the commemorations to mark the 100th anniversary of the start of the Battle of the Somme, northern France, July 1, 2016. REUTERS/Stephane de Sakutin/Pool