The following names are taken from from the charters of the Welsh abbey of Ystrad Marchell from 1176 to 1283. While the charters themselves are in Latin, many of the names listed therein are not Latinized. Most of the names are masculine; only one woman was recorded.
I have not attempted to determine name frequency, as many of the charters refer to the same person repeatedly.
The Charters of the Abbey of Ystrad Marchell, edited by Graham C.G. Thomas. Aberystwyth: National Library of Wales, 1997, http://deeds.library.utoronto.ca/cartularies/0106.