The simple answer to this is that since 1974 it has been in Wales. The following is excerpted from “The Modern Cyclopedia” published in Glasgow in 1901:

“Monmouth (Welsh Mynwy), a parliamentary and municipal borough of England, county town of Monmouthshire, is situated in a beautiful valley at the confluence of the Monnow and Wye”

So there appears to be some confusion and this appears to be long-standing. The Laws in Wales Act of 1532 created the Welsh counties but created Monmouthshire as an English county. The later Act of 1542 specifically excluded Monmouthshire from the list of 12 Welsh counties. The King of the time, Henry VIII, was a Tudor monarch and hence Welsh. For this reason there can be no doubt that 500 years ago Monmouthshire was regarded as English.

Thereafter the waters became muddied. Despite the fact that the Laws of Wales Acts were supposed to ensure that an Act for England also included Wales the Wales and Berwick Act of 1746 reminded people that when an Act referred to England that also meant that it included Wales and Berwick-upon-Tweed.

The 19th century Registration Act created a Welsh registration Division consisting of North Wales, South Wales and Monmouthshire. This, along with the parliamentary practice of passing Acts that referred to “Wales and Monmouthshire” started to create ambiguity, although in reality as the 1746 Act made plain Wales was regarded as part of England. So an action taken for administrative tidiness cannot be taken as a change of nation as some would have.

Despite this the Local Government Act of 1933 clearly listed the administrative county of Monmouthshire and the county borough of Newport as being in England.

This Wales and Berwick Act was repealed in 1967 subsequently requiring the Interpretations Act of 1978 which stated that between 1967 and 1974,when an Act referred to England this would also refer to Berwick-upon-Tweed and Monmouthshire. So until 1974 it was clear that Monmouthshire was intended by Parliament to be part of England.

The Local Government Act of 1972 provided that after 1974 Wales would include Monmouthshire.

So after 500 years or so (perhaps more) of being English the people of Monmouthshire were unceremoniously dumped into Wales, there to become the but of crude Welsh Nationalist jokes about their funny habits without any hint of being asked what they wanted.

There was however a referendum on the question of Welsh devolution in 1997. The people of Monmouthshire now had an opportunity to say what they wanted. They voted 67.1% AGAINST devolution. http://bit.ly/6HlTRd

It is because of this that the English Democrats are standing in the Welsh Assembly  elections on the 5th May. Five hundred years of history and a genuine regard for democracy, instead of political cynicism, require that someone gives the people of Monmouth a choice.

For a list of candidates go to http://www.voteenglish.org/2011-monmouthshire