Within easy walking distance of Bluestone is the ruin of Slebech Church, which, in the 12th century, was part of a commandery of the Knights Hospitallers of the Sovereign Order of St John.
A rival order to the more widely-known Knights Templars, the Hospitallers were originally civilians providing hospital care for pilgrims to Jerusalem and the Holy Land. The turbulent times demanded that the Hospitallers also undertook a defensive role, however, resulting in the order becoming one of the foremost military powers of the region, and soon, the medieval world.
In 1113, the Hospitallers were officially recognized by Pope Pascal II, and exempted from the payment of ordinary tithes. Subsequently, they were also freed from the control of bishops, allowed to administer their own justice and, as they were not even affected by national interdicts, their churches became spiritual and civil sanctuaries.
In 1123, Pope Calixtus II declared that two pilgrimages to St Davids equalled one to Rome and three pilgrimages to St Davids equaled one to Jerusalem. The importance the Pope gave St Davids brought pilgrims in their thousands to the rugged coast of west Wales.
Consequently, the Hospitallers established a commandery at at Slebech, on land granted to them between 1148 and 1176 by Robert FitzLomer, Lord of Minwear Manor.
The commandery also possessed a hospice, two mills and a quay on the Eastern Cleddau, and the Hospitallers were later granted ‘all the wood of the manor’, including the site of the Sisters’ House.
In 1546, following the suppression of the monasteries, Slebech was granted to Roger Barlow and Thomas Barlow, along with the sites and lands of the late priory of Pyll and the late monastery of Haverfordwest.
Information on Slebech, the only commandery solely concerned with Wales, is sadly lacking. The old hospice itself was completely destroyed and Slebech Hall built over the site of the commandery. The site of the old church lies between the mansion of Slebech and the river, where its remains can still be seen.