Prince Charles has recorded a special video message to praise the Royal British Legion (RBL) on its centenary.
The Prince of Wales paid tribute to the charity's work and achievements over the past century.
His Royal Highness said: "There are few organisations which hold a place at the heart of society, in the way the Royal British Legion does.
"For 100 years, the Royal British Legion has been a constant, through the annual Poppy Appeal, leading the nation in remembrance and providing a lifelong commitment to every veteran and their families.
"Therefore, I wanted, above all, to offer my sincere and heartfelt gratitude to all those who have helped build this wonderful organisation we know today, and to all those who will be part of its future.
"I would like to wish everyone at the RBL a very happy and special 100th birthday."
Wreath-laying ceremonies and a flypast from the Battle of Britain Memorial Flight will mark the RBL's 100th birthday on Saturday.
Tri-service personnel and Merchant Navy representatives will lay wreaths at London's Cenotaph – replicating what happened in the legion's founding moment in 1921.
Branch members in towns and villages across the UK will lay wreaths, and ceremonies will also be held worldwide, including in Thailand, Malta, Chile, Belgium and France.
As the centenary is on the same day as the FA Cup final between Chelsea and Leicester City at Wembley Stadium, a specially minted 50p poppy coin will be used for the traditional pre-match toss.
Cover image: MOD.