Where did the 1143 date come from, was it a mistake or did something happen then?

According to the Chronicle of St Werburgh of Chester(16th Century), the Abbey of Cwmhir was founded in the year 1143. (This is quoted by J Rees in Ruinated Abbey 1848 referencing The British Museum, Cotton MSS Vespasian; A.V., 33h and Dugdale's "Monasticon" Vol i, P825; (1655-73) Where did the Chronicle of St Werburg get its information from? The modern understanding is that Cwmhir Abbey was founded in 1176 by Cadwallon ap Madog.



Maredudd ap Madog was Lord of Maelienydd 1140-1146

1144 Anglo-Norman conquest of Maelienydd


The Abbey of Cwmhir was a daughter house of Whitland ( It was widely known as Ty Gwyn ar Daf, meaning White House on the Taf, in reference to the country house originally built here before it became a monastic settlement.

Soon after the destruction of the monastery of Bangor-Iscoed, in North Wales, and the slaughter and dispersion of the brethren of that extensive establishment by the Northumbrian Saxons, a religious society was settled at this place under the auspices of Paulinas, son of Urien Reged, a disciple of St. Germanus, in which originated the Abbey of Albalanda, or Whitland, afterwards erected near the site, and called by the Welsh, after the name of the former establishment, Ty Gwyn ar Taf.

However, the Cisterican Abbey is now known not to have been founded in Whitland at all. Whitland was founded on 16 September 1140 by monks from the mother house of Clairvaux.[4] In 1144 it was located at Little Trefgarn near Haverfordwest. It moved to Whitland in about 1155,[5] a site having been granted by John of Torrington. The abbey founded a number of daughter houses in Wales, starting with an abortive foundation at Abbeycwmhir in 1143. In 1164 a group of monks from Whitland founded Strata Florida Abbey. Strata Marcella Abbey was founded from Whitland in 1170, and in 1176 Cwmhir Abbey was re-founded.(Wikipaedia)

All daughter houses, except for the 1143 attempt, were founded after the move of Whitland to Whitland in 1155.

NB  A Maredudd ap Maelgwn was prince of Maelienydd in 1215 under Prince Llywelyn ab Iorwerth of Gwynedd, who then controlled the district. The later charter to the abbey in 1215 caused the confusion and led to the belief that Maredudd had founded the abbey in 1143?