Josias Welch (Welsh) was the second son of John Welch, the famous minister at Ayr and his mother was a daughter of John Knox. It is most likely that he was at St Andrew's University, but he went to Ulster because he would not follow the Articles of Perth. Robert Blair wrote, "...I meeting with him in Scotland and perceiving of how weak a body and of how zealous a spirit he was, exhorted him to haste over to Ireland where he would find work enough, and I hoped, success enough." Howie said of him "he was called 'the Cock of the Conscience' ... because of his extraordinary awakening and arousing gift.' Strangely he was never sure of his own salvation, saying, "That minister was much to be pitied, who was called to comfort weak saints, and had no comfort himself." He came to Ulster around 1625. He was appointed to the Templepatrick area by Captain Norton, the owner of Castle Upton. He arrived just as the Six Mile Water Revival was beginning in Oldstone, so he hurried there to help in the work.
Castle Upton (then called Castle Norton) was originally built in 1611, on the site of a Knights Templar Castle, by Captain Norton, but he sold it in 1625 to Henry Upton.