The Duke of Sussex has paid tribute to hero Matthew Talbot, 22, of the Coldstream Guards, in a moving ceremony on day eight of the royal tour of Africa.
Guardsman Talbot, died in Malawi's Liwonde National Park on May 5, and was part of the British Army's counter-poaching team, on his first operational deployment.
The patrol of armed British soldiers and African park rangers was walking through tall grass when they disturbed an unseen herd of elephants. One of them charged at Gdsm Talbot who died soon after from his injuries.
'The Duke laid the wreath on behalf of the Talbot family, and said he was honoured to be able to do so, as he has worked closely with park rangers in these efforts and celebrates each and every one of them as heroes' Kensington Palace said in a statement.
It added: 'Often away from the public eye, many people are prepared to put themselves in harm's way, in a bid to protect wildlife from poachers'.
The rangers fired shots and lit bangers to scare off the elephants but it was too late to save the soldier, who died shortly afterwards.
Harry has written to his family on two occasions and took a plaque they commissioned for the memorial with him when he travelled to Africa.
The duke's handwritten message attached to the wreath read: 'In grateful memory of Guardsman Talbot who made the ultimate sacrifice in the service of his country and conservation. Rest in Peace.'
Troops from the 2nd Battalion Royal Gurkha Rifles, the latest contingent of British troops to take part in anti-poaching operations in Malawi, were formed up near the memorial as a mark of respect.
Brigadier Tom Bateman, in charge of all counter-poaching deployment, gave a brief eulogy to the guardsman he knew, and before laying a wreath said: 'Mathew Talbot was a young soldier in the early stages of his career as a Coldstream guardsman.
'Fired with enthusiasm for conservation and specifically counter-poaching, his professionalism, personal courage, was a hallmark of who he was.
'He wanted nothing more than to deploy with his battalion, who are scheduled to go on operations in Iraq next year.
'His selflessness in the face of adversity and his unique humour are typical of the characteristics of a British Army soldier - and we're all immensely proud of him.
'It's a sad day when we must gather to commemorate such a young brave life.'
Prince Harry first visited Liwonde in 2016 and took part in an operation moving elephants 200 miles to another reserve.
He also observed anti-poaching projects there, spending almost three weeks working on the initiative. He described being around elephants as a unique and wonderful experience.
Earlier today it was announced that the prince Harry will guest edit the Instagram account for National Geographic today to raise awareness of the role trees play in the earth's eco-system.
The duke will manage the magazine's social media platform to launch a campaign called 'Looking Up', and will invite users to share their own pictures of trees from around the world.
The prince will work with National Geographic photographers to highlight indigenous trees and how crucial they are to life on earth.
The Duke of Sussex makes a speech at a reception at the British High Commissioner's Residence in Lilongwe, Malawi last night. He is currently on the eighth day of his official tour
He will also share an image taken in Liwonde National Park, Malawi, where he is unveiling two initiatives to help preserve trees in the area.
Buckingham Palace said that Harry's passion for trees and forests is 'inspired by the work he does on behalf of his grandmother, Her Majesty Queen Elizabeth II.'
The 'Queens Commonwealth Canopy' was launched in 2015, when Commonwealth countries were invited to submit forests and national parks or plant trees to preserve in The Queen's name.
Harry is currently on the eighth day of his ten day official tour in Africa.
Harry and Meghan have their own Instagram account, where they share charity posts and upload recent pictures of their son Archie.
Today the Duke of Sussex said conservation is 'fundamental to our survival' and should not be dismissed as 'hippy'.
Writing in the Daily Telegraph on Monday, Harry said that to make progress humans needed to overcome 'greed, apathy and selfishness' and that it was essential to learn from past mistakes to protect the world's most valuable assets.
The Duke also warned of 'vast ecosystems' set ablaze in Africa, communities destroyed for short-term gain, and said that a 'natural order' between humans and wildlife must be restored.
He added: 'This may well sound hippy to some.
'But we cannot afford to have a 'them or us' mentality. Humans and animals and their habitats fundamentally need to co-exist or within the next 10 years our problems across the globe will become even more unmanageable.
'Nature teaches us the importance of a circular system, one where nothing goes to waste and everything has a role to play.
'If we interfere with it, rather than work with it, the system will break down.
'Conservation used to be a specialist area, driven by science.
'But now it is fundamental to our survival and we must overcome greed, apathy and selfishness if we are to make real progress.'
The column comes ahead of his visit to Malawi's Liwonde National Park on the eighth day of a tour of southern Africa to highlight conservation and anti-poaching work.
The duke, who is on a 10-day tour of Africa, yesterday said a major collaborative approach 'across agencies, borders and continents' is needed to end the poaching of Africa's iconic animals such as rhinos and elephants.
At a reception at the official residence of Britain's High Commissioner to Malawi Holly Tett, the duke said on Sunday: 'It is only by working together across agencies, borders and continents that we can finally put an end to the illegal wildlife trade crime that continues to deprive local communities of some of their most valuable natural resources.'
He went on to say, at the event in the capital Lilongwe, that poaching 'hampers development and undermines the rule of law' and praised the nation's ability to track down the poachers.
The duke said: 'Guardsman Mathew Talbot was unfortunately killed a few months ago in the line of duty but the relationship between the British military and the Malawian rangers remains strong.'
Earlier on Sunday the Duchess of Sussex surprised a classroom of female charity workers with a Skype call during Prince Harry's solo visit to Malawi.
Appearing on a television screen in the library of the Nalikule College of Education in Lilongwe, Meghan Markle, 38, waved hello from Johannesburg as the group of young women burst into song for her.
Prince Harry introduced his wife before the surprise appearance, as she joked about their four-month-old son, who has joined them on their 10-day tour of Africa, saying: 'Archie's taking a nap.'
The Duke of Sussex was given a warm and energetic reception at the college on his visit to learn how girls have been kept in school by Campaign for Female Education.
The Duchess, a passionate supporter of gender equality, has not travelled with Harry to the African country, but is in nearby South Africa with their baby son Archie.
It remained uncertain if Meghan would be able to make the video call due to possible technical issues - but she delighted the young female advocates with her appearance, having worked closely with the charity in London.
Before the duchess appeared, Harry told the women: 'I know there's somebody else you'd far rather hear from than me, hopefully if technology doesn't fail us you may see somebody on the screen.'
Meghan was smiling and said: 'I'm so happy to be with you, is there a delay?' and Harry replied 'no, it's great keep going.'
The duchess went on to say: 'We're just so proud as president and vice-president of the Queen's Commonwealth Trust that we can support you in everything that you do because we cannot begin to express how valuable and vital that work is, we're just incredibly proud to be part of it.
'I wish I could be with you, we're in South Africa right now, Archie's taking a nap. I'm with you in spirit.'
On his arrival to the college, Prince Harry joked with pupils as they waved the Union Jack and Malawian flags. A video posted to the official Instagram page of the Duke and Duchess of Sussex shows the choir singing and dancing as Harry watches on in delight.
Despite being seen at the airport on Saturday, there are no official engagements planned for the Duchess in Johannesburg until Tuesday.