The constituency was created by the Redistribution of Seats Act 1885 for the 1885 general election, which divided into three constituencies, the Monmouthshire constituency that had elected two members until 1885. The constituency was abolished for the 1918 general election, when most of its area became the Monmouthcounty constituency.
In 1852, the old constituency had elected members of two powerful families - the Morgans of Tredegar and the Somerset dukes of Beaufort. In 1885, the Morgan interest continued with the election of Colonel Hon. Frederick Courtenay Morgan as MP from 1885 until 1906 when he retired. His son, Courtney Morgan, afterwards Baron Tredegar attempted to succeed him, but was defeated by another local landowner Colonel Ivor Herbert of Llanarth, Monmouthshire. Herbert retained the constituency until 1917 when he departed to the House of Lords. The constituency was abolished a year later.
General Election 1914–15:
Another General Election was required to take place before the end of 1915. The political parties had been making preparations for an election to take place and by July 1914, the following candidates had been selected;