Two ceremonies have marked 20 years since the start of UK operations in Afghanistan.
Wreath-laying events have been held at the Bastion Memorial at the National Memorial Arboretum (NMA) in Staffordshire, and at the Iraq and Afghanistan Memorial in London.
Respects were paid to the sacrifices of 150,000 Armed Forces members who served in the country since 2001, including 457 who lost their lives.
Speaking at the NMA, Armed Forces Minister and Afghanistan veteran James Heappey gave his reaction.
"It's hard. As the trumpeter was blowing Last Post, in my eye line were names from my regiment on the tour following me," explained the former Army Major.
"After the ceremony, I knelt down and there were the names from the summer of 2009 – and they're people I know.
"They're not names on the war memorial in my village, which are from wars of 50 and 100 years ago.
"They're people that I remember on the morning of their death. They're people that I served alongside."
Mr Heappey had not previously visited the Bastion Memorial in East Staffordshire, a reconstruction of the Bastion Memorial Wall at the original camp which carries the same names of the fallen engraved on granite plaques.
"You see the cross that, the last time I saw it, was made out of ammunition rounds that were used on operations in Afghanistan," he added.
"A lot of memories come back. It's hard."
Watch: Armed Forces Minister and Afghanistan veteran James Heappey talks about the emotional occasion.
The anniversary marks the start of US-led coalition airstrikes in Afghanistan, in response to the 9/11 attacks in the US.
The UK joined the NATO mission to uphold human rights and prevent Afghanistan from becoming a breeding ground for further terrorism.
Defence Secretary Ben Wallace said: "Today we remember the sacrifice and courage of the 457 service personnel who lost their lives during the 20 years of UK operations in Afghanistan.
"We remember their bravery in conflict and their dedication to the cause of peace and democracy.
"Their selfless sacrifice transformed Afghanistan and showed the UK's solemn commitment to standing with our NATO allies."