The town of Llandeilo is located in the county of Carmarthenshire, situated at the crossing of the river Tywi. The name `Llandeilo? is named after the Celtic saint of the 6th Century, Saint Teilo who was a contemporary of Saint David and established a small monastic settlement on the site of the present day church. Dinefwr Castle overlooks the River Tywi and lies on the ridge on the northern bank of the Tywi, with a steep drop of over several hundred feet to the river. By the early 12th century Llandeilo came under the patronage of the Bishopric of St David's, an ecclesiastic borough which became responsible for the affairs of the town including its development as an important medieval market centre to an extensive agricultural hinterland.

Until the middle of the 20th century, a fair called St Teilo's Fair, authorised initially by Edward I in 1290 was held annually in the churchyard. Some of the agricultural produce and other goods offered for sale are recorded and are displayed on the tombstones. Today the fair has been replaced by a small farmers' market, held on the first saturday of every month in the same place.

M. Lloyd Davies, RCAHMW, 05 January 2009.