Scouting in Monmouthshire started around 1922 and has progressed to the present, in line with other areas of the United Kingdom.
The National Structure of the Scout Movement in England and Wales follows the Local Government structure of Counties, Boroughs and Districts and as local government boundaries changed the District adapted. The 1989 structural change formed the Marcher Castles District from the previous three separate Districts of Abergavenny, Chepstow and Monmouth. This structure had the advantage of making this Scout District coterminous with its supporting local authority of Monmouth Borough Council.
1996 saw further changes to local government, the emergence of the Monmouthshire County Council, and once more the Scout Movement restructured itself to accommodate the movement of boundaries, and in some cases the names of the Scout Districts to give them a geographical identity.
Monmouthshire District provides Scouting to the youth of the communities that make up Monmouthshire as part of the Voluntary Sector of the Youth Service.
The District stretches from Gilwern in the west to Monmouth in the east, and from Magor and the Severn Estuary in the south to Abergavenny anf The Black Mountains in the north. At one time there were groups further north at Crucorney.