The office of High Sheriff of Gwent was established in 1974 under section 219 of the Local Government Act 1972, replacing the shrievalty of Monmouthshire.
References
High Sheriff of Gwent Wikipedia(Text) CC BY-SA
The office of High Sheriff of Gwent was established in 1974 under section 219 of the Local Government Act 1972, replacing the shrievalty of Monmouthshire.