late 14c., maisterful, "fond of being a master, high-handed, despotic, controlling, imperious, overbearing, tyrannous," from master (n.) + -ful. Sense of "competent, masterly, expressing or indicating mastery" is from early 15c. That of "characterized by a master's skill" is from 1610s. Related: Masterfully. Compare Dutch meesterlijk, German meisterlich, Danish mesterlig.
masterful) (masterly. Some centuries ago both were used indifferently in either of two very different senses: (A) imperious or commanding or strong-willed, & (B) skilful or expert or practiced. The differentiation is now complete, -ful having the A & -ly the B meanings; & disregard of it is so obviously inconvenient, since the senses, though distinct, are not so far apart but that it may sometimes be uncertain which is meant, that it can only be put down to ignorance. [Fowler, "A Dictionary of Modern English Usage," 1926]