Kirkby Ireleth is sited on the peninsula of Furness, in southern Cumbria. The site of the church is listed variously by modern authors as ‘Kirkby Ireleth’, ‘Kirkby-in-Furness’ and ‘Beckside’. It has been dedicated to St Cuthbert since at least the 15thc., but there is some evidence that in the 14thc. it was dedicated to St Mary. The church consists of a nave with S porch, chancel, large north aisle and west tower, the latter built in 1829. Restorations were carried out in 1881, 1884 and 1904. The only surviving Romanesque carving is found on the S doorway of the nave, although the western part of the chancel, with its restored N window and blocked S window, as well as some walling of the nave are also believed to date from the 12thc.

In Domesday Book, Kirby Ireleth seems to have gone by the name Gerleworde, with Earl Tostig having 2 carucates there. At that time it was part of Yorkshire. In the Coucher Book of Furness Abbey it appears as ‘ecclesiae de Kirkeby Hirelithe’ (no. CLXXX) and ‘ecclesiaie de Kirkeby Irelith' (no. CLXXXI); in the Taxatio Ecclesiastica of 1291-2 the listing is: ‘Vicaria de Kyrkeby Irelith que est de Communia Ecclesie Ebor'. The name Kirkby signifies a settlement with a church. Ecclesiastically, Kirkby Ireleth lay in the deaconry of Furness in the archdeaconry of Richmond of the diocese of York. One finds mention of the family of ‘de Kirkby‘ from the 12thc., with Roger de Kirkby, lord of the manor, the first to have taken that name. Roger had at least two sons who appear later in documents: William and Alexander. Another Roger, who seems to first appear during the reign of King Henry II. (VCH 8, fn. 12), is possibly the same Roger who was parson of Kirkby Ireleth (Coucher Book, p. 711) who appeared as a witness for both William and Alexander. In about 1190, there was a release of any claim to the advowson made by William de Kirkby to the monks of Furness Abbey, at which time it was also stated that Roger the parson should retain the church as long as he lived. Furness Abbey is likely to have first acquired it about 1160-80 (VCH, 2, p. 10 fn.). Alexander de Kirkby acknowledged it as such about 1226, but in 1228 it came into the possession of Archbishop de Gray, who in 1230 gave it to York Minster. It was to remain a peculiar of York Minster for the rest of the medieval period.

The Honour of Lancaster, in which Kirkby Ireleth lay, was given to Stephen (later king) by King Henry I at an uncertain date in the first quarter of the 12thc. Lancashire, as such, did not exist at this time. King David of Scotland acquired the honour sometime between 1136 and 1139 as part of a peace agreement with King Stephen. It appears, however, that David did not maintain possession of all of the honour, but does seem to have held that part north of the Ribble until 1149, when it may have been transferred to Ranulph Meschin, earl of Chester. By 1155 it was held by King Henry II, though not long afterwards it was in the possession of William de Warenne IV (son of King Stephen). After William’s death in 1159, the honour formed part of the dowry of his widow, Isabel de Warenne, who married Henry II’s illegitimate brother in 1164. It was then taken back by the crown and remained as such throughout the rest of Henry’s reign. Under King Richard, the honour was granted to his brother John. It remained in John’s hands for five years, but was then taken back by the crown.

Pevsner and Hyde, as well as Historic England (in the listed building description) suggest a date of about 1170 for the doorway, which date seems not unreasonable given the known history and advanced capital forms used on the doorway. However, a date some years later than 1170 is also possible.

Ryder describes a grave cover found during 19thc. restorations on the church. He suggests that this is the grave cover of Alexander I de Kirkby, who died during the first half of the 13thc.

The historical evidence, dating suggestions and probable burial of various members of the de Kirkby family from an early date suggest that the person responsible for the construction of the 12thc. church was a member of this family. It is not unlikely that this was Roger de Kirkby, the first member of the family mentioned in documents as 'de Kirkby' of Kirkby Ireleth.

Farrer (1902, p. 303 top) suggested that Roger Bristwald, who appears in the 1127 foundation charter of Furness Abbey, was the person who later become known as Roger de Kirkby. This is Farrer's personal theory, but nothing has been found to prove it.

Beakhead in the form of a bird's head originates in SW England, from where it spread to various parts of England, especially Yorkshire, and elsewhere. In Cumbria there are three other churches (besides Kirkby Ireleth) known to have used this specific form: Caldbeck, Crosscanonby and Burgh-by-Sand. Kirkby Ireleth is unique in its use on the peninsula of Furness. In Lancashire it is found, now very weathered, at Overton.