To inform the consideration of The Inventory of Historic Battlefields in Wales , documentary and historical research was commissioned on the 1157 battle of Coleshill and the resulting research report provides a detailed overview (Border Archaeology).

The battle of Coleshill represented the single major engagement fought during Henry II's campaign in North Wales. The object of the campaign was to check the advances of Owain Gwynedd, prince of Gwynedd, in north-east Wales.

The actual events of the battle are described at length in the Breviate Chronicle :

'henricus Rex anglie norwalliam dicioni sue uolens excercitum ad campestria cestrie duxit ibique tentoria fixit ? owinus princeps Norwallie cum filiis suis ? hoelo ? canano et dauid cum ingenti excercitu apud d{in}as bassing castra metati sunt ibique uallum erexerunt ? hoc audito rex astuta fretus industria ad uallum owini uia littorea tetendit sed antequam peruenisset a conano et dauid hoc idem precauentibus acerimo certamine susceptus est multisque suorum a{missi}s quo tend{e}bat euasit ? owin{us} audiens regem sibi a tergo imminere in facieautem excercitum regis nimium uallum deseruit et in loco tuciori se receipt' (Gough-Cooper, b1180.1-.2).

Translation: 'King Henry of England, to spread his will into North Wales, led an army into the open plain of Chester, and there he pitched his tents. Prince Owain of North Wales and his sons Hywel, Cynan and Dafydd, with a huge army marked out a military camp at Dinas Basing and there built a great entrenchment. This I have often heard, the king with diligence acted cunningly, he pressed on up the seashore road to Owain's entrenchment; but before he reached it he turned aside. Cynan and Dafydd with those guarding against this gave a sharp battle, and many of the king's men were killed, those who pressed on evading death. Owain heard that the king himself was threatening his rear, while he faced the bulk of the king's army, and so he abandoned his entrenchment and fell back to a safe place' (Remfrey, 180-81).

Two poems written by Cynddelw Brydydd Mawr , shortly after the battle, provide evidence for the location. The first locates it `oddis llaw llys Bennardd? (below the court of Pennardd) and the second `rhag Pennardd? (at the rampart of Pennardd) (Gruffydd). Penardd is the Welsh name for Hawarden, situated in the commote of Coleshill. Gerald of Wales in his Itinerarium Kambriae , compiled around 1191 adds further detail:

Translation: 'In a narrow [heavily] wooded pass near Coleshill' (Thorpe, 189)

This maybe correspond to the wood `koed Pennardlaoc `(Hawarden Wood) noted in the Peniarth 20 version of [titleBrut y Tywysogion (Jones).

The site of the battle remains uncertain. There is conflicting evidence for both the location of the wood where Henry II and his troops were ambushed by Owain's sons Cynan and Dafydd, as well as the site of Owain's fortified position at `Basingwek? (Dinas Basing).

The battle most likely took place between the fortification at Dinas Basing and Hawarden and a site in the vicinity of Ewloe (SJ 28 67), provides the best fit for the available evidence (Edwards).

RCAHMW (Battlefields Inventory), Jan 2017

Bibliography
Border Archaeology, Coleshill (1157): Documentary and Historical Research Report (2009).
Edwards, J. G., `Henry II and the Fight at Coleshill: Some Further Reflections?, Welsh Historical Review, v.3 no. 3 (1967), 251-63.[/ref]
Gough-Cooper, Henry (ed.) The Breviate Chronicle: Annales Cambriae, The B Text from London, National Archives, MS E164/1, pp. 2?26, online edition.
Jones, Thomas (trans.), Brut y Tywysogyon or The Chronicle of the Princes Peniarth MS. 20 Version (Cardiff, University of Wales Press, 1952).
Gruffydd, R. Geraint, `A Welsh poet falls at the battle of Coleshill, 1157: Cynddelw Brydydd Mawr's elegy for Bleddyn Farrd of Powys?, Flintshire Society Journal, 36 (2003), 52-58.
Remfry, Paul M. Annales Cambriae: A Translation of Harleian 3859: PRO E. 164/1: Cottonian Domitian, A1: Exeter Cathedral Library MS.3514 and MS Exchequer DB Neath, PRO E. 164/1 (Castle Studies Research, 2007).
Thorpe, Lewis (trans.), Gerald of Wales The Journey through Wales and The Description of Wales (Penguin, Harmondsworth, 1978).