Mapping Mountains – Significant Name Changes – 200m Twmpau and Y Trechol – The Dominant Hills of Wales

Mynydd Llwyd (ST 433 935)

There has been a Significant Name Change to a hill that is listed in the 200m Twmpau and Y Trechol – The Dominant Hills of Wales, with the summit height, bwlch height, their locations, the drop, dominance and status of the hill derived from detail on contemporary and historic Ordnance Survey maps.

The criteria for the two listings that this name change applies to are:

200m Twmpau - Welsh hills at or above 200m and below 300m in height with 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.

Y Trechol - The Dominant Hills of Wales - Welsh P30 hills whose prominence  equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height, with the Introduction to the Mapping Mountains publication of this list appearing on the 3^rd December 2015, and which is now available in its entirety on Mapping Mountains in Google Doc format.

The hill is adjoined to the Gwent Is Coed group of hills which are situated in the south-eastern part of South Wales (Region C, Sub-Region C3), and it is positioned with the A449 road to its west, the A48 road to its south and the B4235 road to its north-east, and has the city of Casnewydd (Newport) towards the west south-west.

Extract from the Ordnance Survey 1:25,000 Explorer map

The hill appeared in the original 200m Welsh P30 list on Geoff Crowder’s v-g.me website under the name of Gray Hill, which is a name that appeared near the summit of this hill on Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps of the day.

Gray Hill

273m

ST434935

171/172

14

275m on 1986 1:50000 map

Since publication of these P30 lists on Geoff Crowder’s v-g.me website there have been a number of Ordnance Survey maps made available online, some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website, whilst others are current and digitally updated such as the Vector Map Local that used to be hosted on the Geograph website and which is named the Interactive Coverage Map.  Two of the historic maps now available are the Ordnance Survey Draft Surveyors map which formed the basis for the first publicly available Ordnance Survey One-Inch ‘Old Series’ map, and it is these maps that form the basis for the change in this hill’s listed name.

The Draft Surveyors maps consist of the preliminary drawings made by the Ordnance Surveyor’s surveyors between the 1780s and 1840 and formed the basis for the first publicly available One-Inch map.  They were drawn at scales of six inches to the mile for areas considered of particular military significance and down to two inches to the mile for other areas.  Fair copies were then produced from these preliminary drawings to one inch to the mile and then copper plates were prepared for printing.  The Draft Surveyors maps for the whole of Wales are now available online and they form an important part in the study of Welsh upland place-names as they bridge the time frame between the late 18^th century and the mid-19^th century when the Ordnance Survey produced their first One-Inch maps, and importantly for this hill and its listed name, this map gives the Welsh version, along with its English counterpart.

Extract from the Ordnance Survey Draft Surveyors map

The One-Inch ‘Old Series’ map was the first map that Ordnance Survey produced, and their publication culminated from the whole of Britain being surveyed between 1791 and 1874 and the detail gathered therein produced at a scale of one inch to the mile and published in sheet format between 1805 and 1874.  The One-Inch ‘Old Series’ maps for the whole of Wales are now available online; they are also available in map format as enlarged and re-projected versions to match the scale and dimensions of the Ordnance Survey 1:50,000 Landranger series and are published by Cassini.  This series of maps form another important part in the study of Welsh upland place-names and bridge the timeframe leading up to the production of the Ordnance Survey base map of the Six-Inch series, and again, this map gives the Welsh version of this name; Mynydd Llwyd, along with its English counterpart.

Extract from the Ordnance Survey One-Inch 'Old Series' map

The intricacies of language and prioritising one in favour of another for listing a hill is fraught with complication, with originating Cymraeg names being anglicised and also originating English names being cymricised, examples such as these are more common in border country and especially so for anglicised forms.  There is no steadfast rule that fits all, but as a standard a name that has its origins in the Welsh language should be prioritised in favour of a contemporary anglicised or English version of the name, and ideally for this to be substantiated by either historic documentation and / or contemporary usage.  Likewise, if a name exists where an element of it is in English and if this name applies to a hill that is situated in a Welsh speaking part of Wales it is standard practice to use a full Welsh term for the name.  It is also standard practice to use a Welsh name for a hill if another name exists that has originated in a different language.

Therefore, the name this hill is now listed by in the 200m Twmpau and Y Trechol – The Dominant Hills of Wales is Mynydd Llwyd, and this was derived from the Ordnance Survey Draft Surveyors map and the One-Inch ‘Old Series’ map, with the Welsh name for this hill prioritised over its English counterpart, which for listing purposes is standard practice.

The full details for the hill are:

Group:  Gwent Is Coed

Name:  Mynydd Llwyd

Previously Listed Name:  Gray Hill

OS 1:50,000 map:  171, 172

Summit Height:  275m (spot height)

Summit Grid Reference:  ST 43399 93559 (hand-held GPS via DoBIH)

Bwlch Height:  c 183m (interpolation)

Bwlch Grid Reference:  ST 42894 93984 (interpolation)

Drop:  c 92m (spot height summit and interpolated bwlch)

Dominance:  33.45% (spot height summit and interpolated bwlch)

Myrddyn Phillips (May 2020)