William Veitch was born on 27 April 1640. He was the youngest son John Veitch, the minister of Roberton, Lanarkshire. He was educated at the University of Glasgow, graduating with an M.A. in 1659. He became a tutor in the family of . He was licensed to preach by the Presbytery of Lanark in 1664. Having identified himself with the Pentland Rising, he was outlawed, and escaped to Newcastle, where he became chaplain in the family of the Mayor. In 1671 he was ordained to a meeting-house at Fallowlees, a remote spot among the Simonside Hills, Rothbury. From that he removed to Hanamhall, in the same district, and afterwards to Seaton Hall, Longhorsly. Whilst living at the latter place under the assumed name of William [or George] Johnston, he was arrested on 16 January, and sentenced to the Bass