The early Christian settlement that developed around the Saint Teilo's Church prospered, and by the early 9th century it had attained considerable ecclesiastical status as the seat of a Bishop-Abbot. The Church of St Teilo soon became a 'mother church' to the surrounding district, acquiring an extensive estate, and possessing one of Wales' most beautiful and finely illustrated manuscripts – the "Gospel Book of Saint Teilo". The discovery of fragments of two large Celtic crosses from this period provides further testimony to Llandeilo's importance and indeed prestige as an early ecclesiastical centre.