Britain's last surviving veteran of the World War One trenches, Harry Patch, has died at the age of 111His passing comes a week after the death of another of the few remaining survivors of the conflict, and the world's oldest man, Henry Allingham, who died aged 113.The sole British-born survivor of the four year conflict is now seaman Claude Choules, who lives in Australia.Patch, a former plumber, was conscripted as an 18-year-old, and served in the trenches of Ypres on the Western Front, where he was injured and saw three of his closest friends killed in the battle of Passchendaele.Prince Charles, who is also the Duke of Cornwall, paid tribute to Patch who served with the Duke of Cornwall's Light Infantry.Patch, who served as a machine-gunner for four months in the summer of 1917, did not speak about his war experiences until he turned 100, and in his later years he promoted peace and reconciliation.