I may be wrong but the earliest reference that I can find to the phrase “Who will rid me of this meddlesome priest?” is in 1964 when Peter O’Toole says it.
Robert Dodsley's Chronicle of the Kings of England (1740) gives the quote as "O wretched Man that I am, who shall deliver me from this turbulent Priest?," but there's actually a contemporary source to the events that quoted the King as saying, "What miserable drones and traitors have I nurtured and promoted in my household who let their lord be treated with such shameful contempt by a low-born cleric!"
