dickson was first chaplain to robert henley, 1st earl of northington, who became lord-lieutenant of ireland 3 june 1783, and was promoted to the bishopric of down and connor by patent dated 12 december following. he was indebted to fox for this rapid promotion, and richard mant says the news came in a letter to this effect: "i have ceased to be minister, and you are bishop of down". dickson was thus the official superior of his father, who was still dean of down.