Caereinion (fort of Einion) was a medieval

cantref A cantref ( ; ; plural cantrefi or cantrefs; also rendered as ''cantred'') was a Wales in the Early Middle Ages, medieval Welsh land division, particularly important in the administration of Welsh law. Description Land in medieval Wales was divid ...

in the

Kingdom of Powys The Kingdom of Powys (; ) was a Welsh successor state, petty kingdom and principality that emerged during the Middle Ages following the end of Roman rule in Britain. It very roughly covered the northern two-thirds of the modern county of Pow ...

, or possibly it was a

commote A commote (, sometimes spelt in older documents as , plural , less frequently )'' Geiriadur Prifysgol Cymru'' (University of Wales Dictionary), p. 643 was a secular division of land in Medieval Wales. The word derives from the prefix ("together" ...

(''cwmwd'') within a cantref called Llŷs Wynaf. It was divided into the manors of Uwch Coed and Is Coed. It lay towards the south of the kingdom, bordering with the commote of Mochnant Uwch Rhaeadr of the cantref of

Mochnant was a medieval cantref in the Kingdom of Powys. In the 12th century it was divided into the commotes of Mochnant Is Rhaeadr (in the north) and Mochnant Uwch Rhaeadr (in the south) (''Is'' signifying 'below' and ''Uwch'' 'above' the River Rhaeadr) ...

and the cantref of Mechain to the north, the commotes of Ystrad Marchell and Llanerch Hudol in the cantref of Ystlyg to the east, the cantrefi of Cedewain to the south and Cyfeiliog to the west. It roughly corresponds to the later

hundred 100 or one hundred (Roman numerals, Roman numeral: C) is the natural number following 99 (number), 99 and preceding 101 (number), 101. In mathematics 100 is the square of 10 (number), 10 (in scientific notation it is written as 102). The standar ...

Mathrafal Mathrafal near Welshpool, in Powys, Mid Wales, was the seat of the Kings and Princes of Powys probably from the 9th century until its destruction in 1213 by Prince Llywelyn the Great. Location On the banks of the River Banwy, just above its ...

. Castle Caereinion, Caereinion Fechan, Llanfair Caereinion,

Llanerfyl Llanerfyl is a village and community (Wales), community in Montgomeryshire, Powys, Wales. Located near the River Banwy, the community includes the village of Llanerfyl, several farms and wide tracts of marchland. The southern part of the communit ...

, Llangadfan, Llangyniew and part of

Berriew Berriew () is a village and Community (Wales), community in Montgomeryshire, Powys, Wales. It is on the Montgomeryshire Canal and the Afon Rhiw, near the confluence (Welsh: ''aber'') with the River Severn (Welsh language, Welsh: Hafren, Afon Hafr ...

are within the territory of this cantref.

References

Cantrefs History of Powys {{Wales-hist-stub