The first church in Llansteffan was probably built around 650 by Saint Ystyffan. In Norman times, around 1112, it was rebuilt and around 1170 granted to the Order of Knights Chospitaller in Slebech by Geoffrey Marmion. The donation included a fishery and ferry across the river and was confirmed in 1231-1247, 1328. After the dissolution of the order, the church passed into the hands of the Crown, and then under the private patronage. In 1700, the northern chapel of Lloyds of Lacques was added, stylistically referring to the rest of the building. In the 19th and early 20th centuries, the church was renovated. Subsequent repairs were carried out in 1995-1997, when all roofs were replaced.
Built of limestone rubble, the church consists of a rectangular nave with three spans, a rectangular chancel with two spans, northern and southern transept, a north chapel with three spans, porch on the south side and a west tower with three floors. The oldest part is the nave from the 12th-13th century. From the fourteenth century comes the western part of the chancel and the southern porch, while the fifteenth-century are the transepts and the piscina in the southern wall of the presbytery. The four-sided tower on the western side was built at the end of the 15th or the beginning of the 16th century. It is topped with a parapet on corbels and crenelage, and on the north-east side has a turret with a staircase. The interior of the church was originally covered with wall polychromes, from which only small fragments remained.
Website coflein.gov.uk, St Stephen’s church, Llansteffan.