It corresponds approximately to the present principal areas of Monmouthshire, Blaenau Gwent, Torfaen, and Newport and those parts of Caerphilly and Cardiff east of the River Rhymney. The eastern part of the county is mainly agricultural, while the western valleys had rich mineral resources. This led to the area becoming highly industrialised with coal mining and iron working being major employers from the eighteenth century.
Monmouth • Chepstow • Matherne (Mathern) • Llanvihangel • Magour (Magor) • Goldcliffe (Goldcliff) • Newport • Wentlooge • Llanwerne (Llanwern) • Caerlion (Caerleon) • Usk • Treleck (Trellech) • Tintern • Skenfrith • Grosmont • Witecastle (White Castle) • Raglan • Calicote (Caldicot) • "Biston" (Bishton) • Abergavenny • Penrose (Penrhos) • Grenefield (Maesglas) • Maghen (Machen) • Hochuyslade
The Act also designated Monmouth as the "Head and Shire town of the said county or shire of Monmouth", and ordered that the sheriff's county or shire court be held alternately in Monmouth and Newport.
The historic boundaries are the River Wye on the east, dividing it from Gloucestershire and the River Rhymney to the west dividing it from Glamorganshire, with the Bristol Channel to the south. The boundaries with Herefordshire to the northeast and Brecknockshire to the north were less well-defined. The parish of Welsh Bicknor, was an exclave of Monmouthshire, sandwiched between Gloucestershire and Herefordshire. The area was considered part of Monmouthshire until it was made part of Herefordshire "for all purposes" by the Counties (Detached Parts) Act 1844, while the Herefordshire hamlet of Fwthog adjoining the Honddu Valley remained an exclave within Monmouthshire until 1891.
The county contained the three boroughs of Monmouth, Newport and Usk.
New forms of local government were established in the urban areas of the county with the setting of local boards under the Public Health Act 1848 and Local Government Act 1858. The Public Health Act 1875 divided the rural areas into rural sanitary districts.
An administrative county of Monmouthshire, governed by an elected county council, was formed in 1889 under the terms of the Local Government Act 1888. The administrative county had similar boundaries, but included the Beaufort, Dukestown, Llechryd and Rassau areas of south Breconshire. The county council was based in Newport, rather than the historic county town of Monmouth. In 1891 the borough of Newport achieved county borough status and therefore left the administrative county, although the Shire Hall continued to be based there. In the same year the parish of Fwthog was transferred to both the administrative and geographic county of Monmouthshire.
|Urban districts||Abercarn • Abergavenny • Abersychan • Abertillery • Bedwellty • Blaenavon • Caerleon • Chepstow • Ebbw Vale • Llanfrechfa Upper • Llantarnam • Nantyglo and Blaina • Panteg • Pontypool • Rhymney • Risca • Tredegar • Usk|
|Rural districts||Abergavenny • Chepstow • Magor • Monmouth • Pontypool • St Mellons|
In 1899 Abergavenny was incorporated as a borough. Two further urban districts were formed, Mynyddislwyn in 1903, and Bedwas and Machen in 1912. The County of Monmouth Review Order 1935 revised the number and boundaries of the urban and rural districts in the administrative county. A new Cwmbran urban district was formed by the abolition of Llanfrechfa Upper and Llantarnam UDs, Abersychan and Panteg UDs were absorbed by Pontypool urban district, and Magor and St Mellons RD was formed by a merger of two rural districts.
The last major boundary change to affect the administrative and geographic county was in 1938 when the parish of Rumney was removed to be included in the county borough of Cardiff, and therefore the geographic county of Glamorgan.
Monmouthshire's Welsh status was ambiguous between the 16th and 20th centuries, with it considered by some as part of England.
Between about the 5th and 10th centuries the Welsh Kingdom of Gwent covered a broadly similar but variable area. It then became part of Morgannwg, and shortly before the Norman conquest had become part of a unified kingdom of Wales under Gruffydd ap Llywelyn. At the time of the Domesday Survey in 1086 the Chepstow and Monmouth areas were, for accounting purposes, reckoned as parts of the English counties of Gloucestershire and Herefordshire respectively. These areas, along with the rest of what would later become Monmouthshire, were subsequently included in a substantial swathe of land from Pembrokeshire through south Wales to the Welsh Borders which was largely in the hands of the Marcher Lords and not subject to English law. While the Principality of Wales was made part of the Kingdom of England by the Statute of Rhuddlan, enacted on 3 March 1284, the administration of the Marcher lands was unchanged. From the 11th until the 16th centuries, the area which later became Monmouthshire (subject to some boundary revisions) comprised six Marcher lordships - Abergavenny, Caerleon, Chepstow (or Striguil), Gwynllwg (Wentloog), Monmouth and Usk.
The Laws in Wales Act 1535 integrated Wales directly into the English legal system and the "Lordships Marchers within the said Country or Dominion of Wales" were allocated to existing and new shires. Some lordships were annexed to existing counties in England and some were annexed to existing counties in Wales, with the remainder being divided up into new counties, one of which was Monmouthshire.
Although the original Act of 1535 specifically includes Monmouthshire as being in the 'Country or Dominion of Wales' the Laws in Wales Act 1542 enumerates the Welsh counties as twelve in number, excluding Monmouthshire from the count. Neither Act refers to Monmouthshire as being an English county. However, Monmouthshire was added to the Oxford circuit of the English Assizes rather than falling under the Court of Great Sessions in Wales. According to historian John Davies, this arrangement was the cause of the erroneous belief that the county had been annexed by England rather than remaining part of Wales. He also says "Monmouthshire was no less Welsh in language and sentiment than any other eastern county."
Despite Monmouthshire being a new county, it was given two Knights of the Shire in common with existing counties in England, rather than one as in the counties in Wales. The relevant section of the Act states that "one Knight shall be chosen and elected to the same Parliaments for every of the Shires of Brecknock, Radnor, Montgomery and Denbigh, and for every other Shire within the said Country of Dominion of Wales".
Although Wales was legally integrated into England, the word "England" was still taken to exclude Wales in many contexts. The Wales and Berwick Act 1746 ensured that "in all Cases where the Kingdom of England, or that Part of Great Britain called England, hath been or shall be mentioned in any Act of Parliament, the same has been and shall from henceforth be deemed and taken to comprehend and include the Dominion of Wales and Town of Berwick upon Tweed".
The Member of Parliament (MP) for Abertillery, Llywelyn Williams, campaigned to have Monmouthshire unambiguously placed in Wales. Speaking in the House of Commons in February 1957 he said "I think that it is about time we dropped this Wales and Monmouthshire business. Apart from a few cranks who search the files of the distant past for some very flimsy tokens of evidence to suggest that Monmouthshire belongs to England, no person acquainted with the county — its history, customs, place names, culture and way of life — would dream of regarding Monmouthshire people as anything but Welsh." Later in the year he asked Henry Brooke, Minister of Housing and Local Government and Welsh Affairs, "whether he will now remove from official documents and records relating to Wales the additional words 'and Monmouthshire', since Monmouthshire is included in the term Wales.". Brooke replied in the negative, as he did not think "such a course would be consistent with various statutory provisions relating to Monmouthshire."
The Local Government Commission for Wales established in 1958 included Monmouthshire within its review area, and in 1961 proposed merging the area into a new "South East Wales" county. The proposed inclusion of Monmouthshire in Wales infuriated Lord Raglan, by now Lord Lieutenant of the county. In reaction, a "Make Monmouthshire Welsh" campaign was launched in August 1961 to gain parliamentary recognition that the county was in Wales. In November 1961 it was announced that a branch of the Royal Society of St George was to be formed, emphasising the county's English identity. Two years later Monmouth Borough Council made representations to the Minister of Housing and Local Government seeking the transfer of the town to Herefordshire in the event that the reforms were carried out. Signs erected by Monmouthshire County Council welcoming motorists to Wales were defaced or removed.
The Welsh Office, established in 1966, included Monmouthshire within its remit. The Wales and Berwick Act was repealed in regard to Wales in 1967 under the Welsh Language Act 1967. The Interpretation Act 1978 provides that in legislation passed between 1967 and 1974, "a reference to England includes Berwick upon Tweed and Monmouthshire".
In 1969 George Thomas, Secretary of State for Wales proposed to fully incorporate Monmouthshire into Wales. Lord Raglan (son of the former lord lieutenant), asked the following question in the House of Lords: "To ask Her Majesty's Government why they propose to incorporate Monmouthshire into Wales without consulting Monmouthshire's inhabitants." Replying for the government, Baroness Phillips stated that "The purpose of the change is to remove the anomaly arising from the present need to refer to Monmouthshire separately from Wales in Statutes. My right honourable friend the Secretary of State believes that the proposal commands wide support in the county." In April of the following year Plaid Cymru MP Gwynfor Evans asked Thomas "when he proposes to implement his undertaking that the phrase 'Wales and Monmouthshire' " will be dropped." The Secretary of State indicated that it would be after the passing of legislation to reform local government in Wales.
The issue was finally clarified in law by the Local Government Act 1972, which provided that "in every act passed on or after 1st April 1974, and in every instrument made on or after that date under any enactment (whether before, on or after that date) "Wales", subject to any alterations of boundaries..." included "the administrative county of Monmouthshire and the county borough of Newport".
The English Democrats Party nominated candidates for the 2007 Welsh Assembly elections in in the South East Wales region, and three of six constituencies in the area of the historic county with a view to promoting a referendum on 'Letting Monmouthshire Decide' whether it wished to be part of Wales or England. The party received 0.9% of the vote on the regional list, and between 2.2% and 2.7% of the vote in the constituencies and failed to have any members elected.