THE mood in St Paul's Cathedral was not triumphal. Hundreds of immaculately uniformed soldiers, sailors, and air-men and -women, together with relatives of the injured and the dead, sat quietly with assorted dignitaries, as sombre organ music rumbled around them.

They were there on a crisp morning, on Friday of last week, to commemorate the 13-year-war in Afghanistan, and to remember what the conflict had cost.

The Archbishop of Canterbury spoke of the "faithfulness" of those who had fought in Afghanistan, echoing the prophet Jeremiah in the book of Lamentations: "As our nation honours at this service all of you who have served in Afghanistan. . . I ask you to hear those same words today, reverberating around our land: great is your faithfulness.

"We thank you for your faithfulness: you who left family behind . . . you who did not turn from danger, you who suffered injury, and you who risked yourselves to care for the injured. Great is your faithfulness.

"We also thank those of you who stayed behind, who let your loved ones go. . . Great is your faithfulness."

The Chaplain General, the Revd Dr David Coulter, explained how soldiers at Camp Bastion had fashioned a cross out of concrete and brass shell-cartridges as an impromptu memorial to fallen comrades. "Services at this memorial were always poignant, tender, and raw," he said. The same cross was laid on the altar of St Paul's and dedicated by Archbishop Welby. It will eventually be taken to the National Memorial Arboretum, in Staffordshire.

Military chaplains and members of each branch of the armed forces then said prayers for those who had died, for their families, for civilians caught up in the war, and for the "healing of the nations".

The Prime Minister and other leading politicians sat in the front row, alongside the Queen and the rest of the royal family. Close by sat representatives of the Buddhist, Hindu, Muslim, Jewish, and Sikh communities, who later joined the Bishop of London, the Rt Revd Richard Chartres, in an "act of commitment to the common good".

After Archbishop Welby had said a blessing, and the National Anthem had been sung, the audience slowly filed outside the cathedral to watch a parade of forces personnel through the streets of the City of London. Crowds of passers-by filled the pavements, and spontaneous applause broke out as the ranks of uniformed soldiers marched by.

A handful of helicopters and aircraft that had flown in Afghan skies during the campaign then flashed past over the dome of St Paul's.

Dave Hart, who was injured while on service in Afghanistan, told the BBC that the event was for all of those who had died: "I think today really is primarily, for me, about the comrades who didn't come home.

"And those who have come back with injuries - be they physical or mental - and also for their families. It does feel like a closing of a chapter, really."

The father of one soldier who was killed, and posthumously awarded the Victoria Cross, Duane Ashworth, said that Afghanistan had benefited from British soldiers' sacrifices. "It's now for the forces that are there to continue that training with the Afghan forces and police, to make sure what our lads did does continue."

Some UK soldiers are still in Afghanistan, training the Afghan army, and a service was held for them, at the same time, at the Afghan National Officers' Academy. Military bases across Britain and in Germany have also held reflections and commemorations.

Earlier in the day, the President of Afghanistan, Ashraf Ghani, paid tribute to the 453 British troops who had lost their lives in Afghanistan. He said that they had "paid the ultimate sacrifice to enable us to live in freedom, in hope for peace, prosperity, and dignity".