John M'Millan, founder of the Reformed Presbyterian Church, was the son of John M'Millan, who was descended from a branch of the family long settled at Arndarroch. John was born in 1669 at Barncauchlaw, a hill farm in the parish of Minnigaff, Kirkcudbrightshire. His father is said to have fallen at Bothwell Bridge, and his mother, whose name is unknown, married again. M'Millan was probably brought up at Earlston, in Dalry, where he attended the parish school, and met many of those who had suffered for their religious convictions. He studied at the University of Edinburgh, and graduated M.A. 28 June 1697. He was sometime chaplain to John Murray, the laird of Broughton [Cally, parish of Girthon].