Sergeant Mat Hardy of the Third Battalion, The Royal Anglian Regiment, laid a wreath at 9am on the 15th May 2021, exactly 100 years to the minute after their founding at Grimsby Cenotaph.
The charity, which provides support for armed forces members and their families, was established in 1921 after the First World War.
Gail Davy, the Chairman of Grimsby Royal British Legion, was there to witness the moment along with standard bearer Charles Long, bugler Eddie Gibbs and Lieutenant Colonel Paul Woolnough.
Deputy Mayor of North East Lincolnshire, Councillor David Hasthorpe, was also present at the socially-distanced ceremony.
The Royal British Legion say their work is important today as in 1921, and thanked everyone who has supported them over the last 100 years.