Eric Antwerp Jones, from Merthyr Tydfil, has turned 100 today.
He served in 1st Battalion Welsh Guards during the 1930s and 40s.
To mark his birthday milestone, he was treated to a surprise party at his home by current members of the regiment.
Three serving Welsh Guardsmen dressed in their famous red tunics and bearskins visited his home address in Merthyr Tydfil to present him with a special gift, cake and letter on behalf of the regiment.
Watch the moment the Guardsmen surprise Eric at his home
Eric left school aged 14 and worked in a coal mine for five years.
He joined the Welsh Guards in 1934 before being discharged. In 1938 he joined the Merthyr Tydfil Police Force but was recalled to the Welsh Guards at the outbreak of World War II.
He was promoted to Sergeant in 1941.
Eric served with exemplary conduct until 1945 when he had an accident and spent five months in hospital before being finally discharged.
He returned to the police force and served until 1966 before becoming head porter at St Tydfil's Hospital, Merthyr Tydfil for nine years.
When the Welsh Guards surprised him, Eric was left speechless - something his family says is very rare
Later he told ITV News reporter Tom Sheldrick the party was "wonderful".
"I never expected this. It brings back so many memories" he said.