The Templars and the Hospitallers made inroads into Wales, though less than in other European countries. In Wales, they are very much associated with the Normans and the Holy Land … not that Welshmen didn’t go on Crusade, because some did, but that the institution didn’t attract much of a following among the native Welsh.
“In 1156 the Countess of Warwick gave the Templars the church of Llanmadoc in the Gower, and until the early 1280s they held Templeton in Pembrokeshire – contemporary documents call it “Villa Templar”, “Templars’ village”.
William Marshal may have given them the mill they owned outside Pembroke castle, and he may have been the donor who gave them the church of Kemeys Commander on the River Usk. The Templars also owned small parcels of land in Glamorganshire and Gwent.
Though founded at the same time as the Templars, Hospitallers seemed to attract more support among Welsh landowners, perhaps because they provided services to the local people in the form of hospitals, just as they did in Jerusalem. The Hospitallers’ house at Slebech on the Eastern Cleddau river was given to them by a Flemish family who had settled in the area. It was then had a wide range of supporters over the centuries. Slebech became an administrative centre or commandery, the Hospitallers’ fourth richest commandery in England and Wales.
“One of the most powerful political organizations in the late Middle Ages was the Order of St. John of Jerusalem, the Knights Hospitallers, whose ranks were filled by scions of the richest aristocratic families of Europe. Formed in Jerusalem in the 11th Century to provide hospital care and protection to Christian pilgrims visiting the Holy Land, the Knights soon became one of the foremost military powers in the region. Their base of operations was a chain of castles and ports. After Saladin, King of the Saracens, dislodged them from Jerusalem, the Knights relocated briefly to Cyprus, and then to the island of Rhodes in 1309.” http://www.rapidappsgroup.com/history
The preceptory of Halston “was founded between 1165 and 1187, when Roger de Powys, lord of Whittington, granted the Hospitallers a portion of his demesne. By the second decade of the 13th century it was sufficiently well established to be considered by the bishop of St. Asaph a suitable guardian for his hospital at Oswestry …”
Other Hospitaller sites include three in Ceredigion, possibly founded by Richard de Clare before his death in 1136 or one of his descendants during a period of Norman control of the area. These include Ysbyty Ystwyth, Ysbyty Ystrad Meiric, and Ysbyty Cynfyn (Ysbyty means “hospital” in Welsh).
Another site, Ysbyty Ifan, was founded on the Conwy River in 1190. https://coflein.gov.uk/en/site/309304/
By 1294, it had been united with Halston, which became the administrative centre for all Hospitaller estates in north Wales. http://www.british-history.ac.uk/report.aspx?compid=39933