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What would Wales’ elections look like if we went back to the medieval cantrefi? And who would win?

27 Apr 2021 6 minute read
Wales’ cantref map with present-day constituencies overlaid

Ifan Morgan Jones

Last year at the time of the Presidential Election I asked what Wales would look like if it had a US-style Presidential system. And who would win?

You can find the answer here.

Today I want to explore another interesting (i.e. daft but fun) electoral scenario. What would Wales look like if it went back to the original constituencies?

No, I’m not talking about the seats that existed before the last boundary review in 2010. No, I’m not even suggesting going back to pre-1832 Reform Act rotten boroughs.

Let’s go all the way back to medieval Wales when the land was divided into cantrefi.

The cantrefi, thought to be based on earlier kingdoms, were important in the administration of Welsh law because each cantref had its own court presided over by the local top nobs.

There also just so happened to be 42 of these in all – almost the same number of constituencies that exist in Wales today.

And a few of them have names that survive in the constituencies familiar to us today, such as Arfon, Meirionnydd, Penfro (Pembroke), Dyffryn Clwyd (Vale of Clwyd), and Gŵyr (Gower).

Wales’ borders have shifted over time so at least one of these cantrefi, Ergyng, now exists in an area that is altogether outside Wales’ borders.

The rest, however, if recreated, would represent at least some of the denizens of modern Wales.

My understanding of the layout of these cantrefi is based on this map of the cantrefi of Medieval Wales, which took as its source data this map by the Royal Commission on Mapping the Medieval Cantrefi and Commotes of Wales.

Map of the cantrefi of Medieval Wales. Picture by XrysD (CC BY-SA 4.0).

That map is based in South Wales and the Border in the Fourteenth Century (1933) by W.M.Rees. and R.J.P Kain, and R.R. Oliver’s Historic parishes of England and Wales (2001).

I then used Boundary Assist in order to map this data onto the administrative council wards of modern Wales.

In practice, this meant taking the Royal Commission map into photoshop and overlaying it onto a map of modern Wales with modern boundaries and figuring out what should go where.

Unfortunately in some cases, it was impossible to map the cantrefi exactly on to present council wards.

One example of this would be Uwch-Aeron and Is-Aeron – some of the present-day wards, such as Llanfihangel Ystrad, pass over the river Aeron rather than straddling along it as this historic boundary did.

Ynys Môn was the main victim of this problem where the present large, multi-member wards just do not divide in the same way as the old cantrefi did.

But on the other hand, I was often very pleasantly surprised to what extent present administrative boundaries match those of medieval times. In some cases, even present-day constituency borders matched up almost exactly to the medieval cantrefi.

Wales’ Cantrefi in Boundary Assist

There are some obvious reasons for this of course – our present-day constituencies are shaped by rivers, valleys, and mountain ridges just as the cantrefi were in medieval times.

But there were some examples where borders just seemed to be there because they had always been there, particularly in Powys where the shape of the old cantrefi was still seen clearly on preset day wards.


So what electoral impact would going back to the medieval cantrefi have?

Well, it wouldn’t be a particularly representative system because the population of Wales has changed an awful lot since the 14th century.

Some constituencies would serve very small populations and others populations that are, today, absolutely huge.

Most mammoth of all would be Penychen. One of the larger of the cantrefi, in medieval times it served inhospitable valleys, swampy ground and mudflats.

Today it would serve Penarth, Cardiff West, Rhondda and the Cynon Valley. This would give it a massive 301,000 voters, 13% of the entire Welsh electorate.

Also outsized would be Sengheny, serving Cardiff East, Cardiff North, Caerphilly and Merthyr Tydfil, a whopping 270,000 people.

Other constituencies meanwhile would be quite tiny by comparison. Emlyn, now essentially the town of Newcastle Emlyn, would represent only 4,000 people.

Uwch-Aeron, the area between the Aeron River in Ceredigion and Llanddeiniol, would represent only 7,600 people.

The smallest of all would be Ewias in present-day Monmouthshire because most of it was outside Wales and only a small chunk remains within the border. It would have only 1,691 voters – probably the first to declare on election night, then.


So, if Wales held an election under these circumstances, who would win?

Well, I think we would finally have found an electoral system in Wales where Labour would not win. This is because the bulk of their support is wrapped up in just five very big cantrefi.

In fact, I think Labour would probably come last, with Plaid Cymru in second place and the Conservatives in the lead.

This calculation is based on the large number of cantrefi in present-day Brecon and Radnorshire in Powys, Pembrokeshire and the north-east of Wales.

Harder to call are the Gwent Is-coed and Gwent Uwch-goed constituencies which cross from present-day Monmouthshire into Blaenau Gwent and Cwmbran. Tight marginals for Labour and the Conservative perhaps.

Gwarthaf in present-day Carmarthen West and South Pembrokeshire might also be a tight Tory / Labour / Plaid contest.

Ynys Môn is also a tight call as it’s all over the shop electorally, so I’ll give the Tories, Plaid and Labour one cantref each there.

So the final score by my tally would be somewhere around the Tories on 17 cantrefi, Plaid Cymru on 16, and Labour on 10.

Of course, if this electoral system had a second regional vote Labour might make an awful lot of ground back with a hell of a lot of list members.

Does any of this matter? Well, no, not really! But it’s a reminder that despite our world changing completely in the last seven hundred years present-day administrative boundaries often stand on the foundations of ones that go back hundreds if not thousands of years.

The Boundary Commission are getting ready to overhaul our boundaries again in Wales – to reduce the number of MPs from 40 to 32. And also, perhaps, at some point in the future to expand the number of Senedd Members.

Whoever is tasked with completing that task may want to keep these invisible – but strangely enduring – borders in mind when deciding where the new ones go.

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3 years ago

Fascinating. And what evocative names! If the Welsh Government were to re-introduce the word ‘cantrefi’ instead of ‘constituencies’ it would give us a link with the country’s past. Not such a waste of Ifan’s time as he thinks, perhaps.

Alec Dauncey
Alec Dauncey
3 years ago
Reply to  Wrexhamian

You can vote Welsh Liberal Democrat – it’s in the manifesto… 🙂

3 years ago
Reply to  Alec Dauncey

Then that’s greatly to their credit. Whatever constituency set-up is in place after May, the next Welsh Government should bring the word back.

Alec Dauncey
Alec Dauncey
3 years ago

This is what the Welsh Liberal Democrat Manifest for next month says on this subject (obviously a job for the: “We envision a new structure of “Cantrefi” councils through the amalgamation of town and community areas into meaningful and efficient units for public service delivery with greater local accountability and autonomy. We will: ● Instruct the Local Democracy and Boundary Commission for Wales to shape plans for local government reorganisation, through the amalgamation of town and community areas into meaningful and accountable bodies. ● Investigate the creation of a small number of larger regional authorities for parts of Wales with… Read more »

3 years ago

I think the Swiss copied the idea and called them “cantons”.

3 years ago

Which Cantref was Hundred House in I wonder?
I can’t work it out from the maps.

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