Tomen yr Allt
{{Use dmy dates|date=April 2022}}
{{Infobox ancient site
| name = Tomen yr Allt
| native_name =
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| map_type = UK Wales
| map_alt =
| map_caption = Tomen yr Allt within Wales
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| relief = 1
| coordinates = {{coord|52|46|49.33|N|3|17|45.71|W|display=inline,title}}
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| location = Near Llanfyllin
| region = Powys, Wales
| type = Motte and Bailey Castle
| part_of = Kingdom of Powys until 1160, then Principality of Powys Wenwynwyn.
| length = 40 m
| width = 40 m
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| material = Earthwork and timber
| built = Possibly 10th century
| abandoned = 1257 (keep destroyed)
| epochs = Medieval
| cultures =
| dependency_of = Cantref of Mechain
| occupants = Lords of commote of Mechain Uwch Coed
| event = Put under siege by Llywelyn ap Gruffudd in 1257
| excavations = 1978
| archaeologists = Clwyd-Powys Archaeological Trust
| condition = Ruin - only earthworks remaining and very overgrown
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| other_designation = Cadw scheduled monument
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Tomen yr Allt (or Domen yr Allt) was a Medieval motte and bailey defensive castle near Llanfyllin in Powys, Wales.{{cite web|title=Tomen yr Allt Motte, Llanfyllin|url=http://www.gatehouse-gazetteer.info/Welshsites/706.html|website=Gatehouse|accessdate=23 April 2015}} "Tomen ar hallt" is modern Welsh for "mound on the wooded hillside."
Description
The site is over {{cvt|40|m}} in diameter; the central man-made earthwork mound (motte) is about {{cvt|13|by|10|m}} and nearly {{cvt|10|m}} high. There is a continuous stony ditch, which is doubled on the north-east side, away from the natural slope of the hill.{{cite web|title=DOMEN-YR-ALLT/TOMEN-YR-ALLT|url=http://www.coflein.gov.uk/en/site/306791/details/DOMEN-YR-ALLT%3BTOMEN-YR-ALLT/|website=Coflein|publisher=Coflein}} The bank is flattened where it joins fields on the south-east side and no bailey is apparent in that section. Most of the earthworks remain and the keep of the castle was probably timber, as CPAT (Clwyd-Powys Archaeological Trust) found a piece of daub and the remains of a burnt layer in 1978.{{cite web|title=Tomen Yr Allt Motte|url=http://www.cofiadurcahcymru.org.uk/arch/query/page.php?watprn=CPAT1476&dbname=cpat&tbname=core|publisher=CPAT|quote=See also PDF file linked on this summary page}}{{cite web|title=POWYS Archaeological Record Site No. 1476|url=http://www.herwales.co.uk/herumd.php?group=CPAT&level=1&docid=301475078|website=CPAT|date=1976}}{{dead link|date=February 2025|bot=medic}}{{cbignore|bot=medic}} The site is a Cadw scheduled monument.{{cite web|title=Scheduled Ancient Monuments|url=https://www.whatdotheyknow.com/request/scheduled_ancient_monuments_3#incoming-38315|quote=Excel spreadsheet: SAMs by UA.xls: SAM MG027}}
History
{{Annotated image
| image = Parkland at Bodfach Hall - geograph.org.uk - 559379.jpg
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{{Annotation|40|6|Tomen↓}}
| caption = View from Bodfach Hall towards Tomen yr Allt (peak one third of the way across the skyline from the left)
}}
Tomen yr Allt was the caput of the commote of Mechain Uwch Coed in the cantref of Mechain.{{cite journal|last1=Richards|first1=Robert|title=Y domen Gastell|journal=Montgomeryshire Collections Relating to Montgomeryshire and Its Borders.|date=1949|volume=51|page=72|url=http://welshjournals.llgc.org.uk/browse/viewobject/llgc-id:1265339/article/000088724|accessdate=15 April 2015}}
In 1160, when the Kingdom of Powys was divided, Mechain became part of the principality which later came to be known as Powys Wenwynwyn. By 1208, the region was controlled by Llywelyn the Great. After his death in 1241, his heir had to come to terms with Henry III of England, which resulted in Powys Wenwynwyn passing to the rule of Gruffydd ap Gwenwynwyn who was allied to Henry III.
Llywelyn ap Gruffudd, the grandson of Llywelyn the Great and the Prince of Gwynedd, began to expand his territory after 1255. In May 1257, Llywelyn ap Gruffudd was reported to have put the "castle of Bodyddon" under siege (Tomen yr Allt is less than 1 km east of Bodyddon and overlooks it). The intention was likely to bring the lords of Mechain to submission, and by 1258 they were indeed allied to Llywelyn.{{cite book|last1=Smith|first1=J Beverley|title=Llywelyn Ap Gruffudd: Prince of Wales|date=2014|publisher=University of Wales Press|page=99|isbn=9781783160075|url=https://books.google.com/books?id=yl6uBwAAQBAJ&q=Tomen+yr+Allt&pg=PA99}} Presumably Tomen yr Allt is the "castle of Bodyddon" to which the reports refer, which was destroyed in 1257.
The site overlooks Bodfach Hall approximately 1 km south-east in the hamlet of Bodfach near Llanfyllin. Tomen yr Allt and the wooded area around it, known as Coed yr Allt, is on land which belonged to the historical estate of the hall.{{cite book|title=An Inventory of the Ancient Monuments in Wales and Monmouthshire: I - County of Montgomery|date=1913|publisher=Royal Commission on the Ancient and Historical Monuments of Wales|url=https://books.google.com/books?id=DPQLAnNkbPUC&pg=PA95}} The original building on the site of the hall may have been constructed to replace the castle.{{cite web|title=BODFACH HALL|url=http://www.coflein.gov.uk/pdf/CPG365/|publisher=Coflein|accessdate=22 April 2015|url-status=dead|archiveurl=https://web.archive.org/web/20160304052910/http://www.coflein.gov.uk/pdf/CPG365/|archivedate=4 March 2016}}