Little is known about the early history of Penicuik. John Wilson (1891) says the earliest reference to the church that he could find referred to the advowson in the 12thc., which he said belonged to the lord of the manor. It is uncertain from where this information comes. Rymer (1745) lists a Walterus Edger, Persona Ecclesiae de Pemcok, Vicecomitis de Edenburgh as a witness to a 1296 charter of Edward I, believed to be the first definitive documented reference to both Penicuik (which in early records is called Penicok) and to the church. There is no known surviving medieval record for the dedication of the church, though it is assumed that the later references to St Kentigern (St Mungo) are likely to be continuations of the original dedication.