Wikipedia
The Wreocensæte , sometimes anglicized as the Wrekinsets, were one of the peoples of Anglo-Saxon Britain. Their name approximates to " Wrekin-dwellers". It is also suggested that Wrexham also derived from Wreocensæte.
The boundaries of the kingdom are uncertain, but it was substantial as the Tribal Hidage lists it as 7000 hides, equal to the kingdoms of the East Saxons and South Saxons. The evidence suggests that the Wrekinset were the most northerly of the three large Mercian subject kingdoms facing Wales, with the Magonsæte to their south, and the Hwicce farthest south. The chief place was seemingly the former Roman Viroconium Cornoviorum (modern Wroxeter), the former civitas of the Cornovii and close to the hill fort known as The Wrekin. The kingdom may have covered much of modern Cheshire, Shropshire and into North East Wales, Wrexham, Denbighshire and Flintshire. The border between Wales and Wreocensæte would have been Offa's Dyke.
As with the neighbouring Magonsæte, the lands of the Wreocensæte appear to have included a number of lesser tribes or kingdoms. Place-names suggest that the much smaller Meresæte, Rhiwsæte and Halhsæte lay within the lands of the Magonsæte. These, and the more southerly examples in Magonsæte, appear to be spaced regularly along the line of the frontier with Wales, and it is suggested that they may be artificial in origin, created by a king of Mercia to delineate and defend that border.