Between 1162 and 1189, while he was High Constable of Scotland and held Cunningham and Largs from King William the Lion, Richard de Morville granted to James, son of Lambinus, the lands of Loudoun.
For his residence and as the base for his authority, James constructed the great mound overlooking the Hag Burn and set his wooden castle upon it. Shortly afterwards he established a small church (Loudoun Kirk) dedicated to St Michael to provide for the spiritual welfare of the people of Loudoun. In time the wooden castle was replaced by a stone structure, but on its destruction in 1528, the next Loudoun Castle was erected a short distance to the west.
The Loudoun estate passed through marriage first in the 13th century to the Crawford family, then at the beginning of the 14th to the Campbells who held it for centuries. Over time, its owners frequently played major roles locally and nationally.
Loudoun Kirk served the whole parish of Loudoun. Its form was typical of an early Pre-Reformation parish church. Its alignment was east to west. It was small (approx. 19m long by 8m wide), stone built, with a thatched roof to begin with, with a few small windows to cut down as much as possible on draughts (there was no glass), a single door, probably at the western end of the north side, again to assist shelter from the prevailing SW winds. Inside at the east end, within a small chancel area, stood the altar, at which Mass was celebrated, and beside it a bench for the priest and a cupboard for the sacred vessels. The nave floor would have been earthen or slabbed – there were no seats for the parishioners.
The bulk of the revenues of Loudoun Kirk (together with those from other 13 parish churches in Cunningham) were not applied to the needs of the Kirk or parish but had been appropriated by Richard de Morville to support his newly founded Kilwinning Abbey. It was, however the responsibility of the Abbey to supply a vicar or curate to attend to the spiritual needs of the parish.
Loudoun Kirk continued through the War of Independence and may well have seen some of the participants in the conflicts of Wallace and Bruce on the eastern fringes of the parish – but documentary evidence for this period is lacking. After the death of the curate Hugh Crawford before 1465, complaints were being made to the Papal Court in Rome that Kilwinning Abbey had been taking too large a proportion of Loudoun Kirk’s revenues and for too long, and some priests in Rome began to apply for some of these revenues – and the requests were being granted. But although we know the names of several of these applicants, there is now way of knowing how many of them ever set foot in Loudoun Kirk. The real work here was carried out by the curates.
In 1491, James IV erected Newmilns into a free burgh of barony and around 1530, to meet the needs of its growing population, a chapel dedicated to the Blessed Virgin Mary was built there. William Wilson, the curate at Loudoun Kirk, now had two places of worship to attend to, with the help of his parish clerk, Murdoch Nisbet. At the Reformation, the existing chaplain, Rankin Davidson, was approved as a reader by the General Assembly and allowed to continue to minister at Loudoun Kirk and Galston. In 1574, because of the shortage of minister, parishes were grouped together and Loudoun, Kilmarnock and Riccarton were put under the ministry of Mr Robert Wilkie, aided by his reader, James Hall.
In 1601, Sir Hugh Campbell was created Lord Campbell of Loudoun, Baron Loudoun of Loudoun, and when he died in 1622, a burial vault was constructed for him beneath the floor of the chancel in front of the alter. This vault became the resting place of later members of the Loudoun family.
At a still unknown date, Loudoun Kirk lost its status as parish church, and the chapel in Newmilns was upgraded to parochial status. In 1898, the third Marquis of Bute, at the east end of the ruins of the old Kirk, created the elaborate family vault, which has been restored and consolidated in recent years through the dedication and hard work of the Friends of Loudoun Kirk, supported financially by History Scotland and the Heritage Lottery Fund.
The kirkyard has been the resting place of the Loudoun parishioners for centuries and among many others are to be seen the graves of Janet Little, milkmaid and poetess, and Thomas Fleming, Covenanter, as well as the memorial to the tragic Lady Flora Hastings.