A new word: cicerone.

"Years later he [George Otto Trevelyan, the great British Historian] acted as cicerone to his talented son George Macaulay Trevelyan."

From the "Editor's Introduction" by Richard B. Morris of The American Revolution by George Otto Trevelyan, "a condensation into one volume of the original six-volume work." (David McKay Company, Inc. New York 1964.)

cicerone: A guide who conducts sight-seers to places or objects of interests, as museums or antiquities; hence, loosely, a guide.

Morris refers to the elder Trevelyan's travel with the younger through Italy.