Alexander Waverly is the number one of Section I of the United Network Command for Law and Enforcement. He is one of five regional chiefs in charge of the multi-national agency. Waverly apparently is first among equals. In a fourth-season episode, he presides over an annual meeting of the regional chiefs where new codes and other information are exchanged each year (The Summit Five Affair).
In the pilot episode of The Man From U.N.C.L.E., the head of the organization was Mr. Allison, played by Will Kuluva. Producers decided to recast the role. The result: actor Leo G. Carroll was hired to portray Alexander Waverly, now the chief the organization. For the broadcast version of the pilot (The Vulcan Affair), scenes with Kuluva with Robert Vaughn and David McCallum (as U.N.C.L.E. agents Napoleon Solo and Illya Kuryakin) were reshot with Carroll playing Waverly.
Waverly is an alumnus of Blair University (The Cap and Gown Affair). He evidently was a ladies man in his day. His cousin, Lester Baldwin, witnessed an "indescretion" involving a young woman. Details were never revealed (The Bow-Wow Affair). Also, he had a relationship with a woman in Greece (The It's All Greek to Me Affair).
Waverly may have the appearance of a university professor, but that belies his own toughness and, if necessary, ruthlessness. He deliberately keeps enforcement agent Napoleon Solo in the dark during an assignment (The Foxes and Hounds Affair). The U.N.C.L.E. chief also is ready to order the bombing of a Carribean island that is the base of a Thrush operation to alter the jet stream. When Solo objects that fellow agent Illya Kuryakin and an "innocent" are on the island, Waverly says the enforcement agent can resign if he's not prepared to follow instructions (The Concrete Overcoat Affair Part II). Waverly does permit Solo to attempt a rescue operation, but the agent won't have any help from U.N.C.L.E. Waverly then comments to himself that he must be going soft. Hardly.
Waverly's position means he is sometimes in jeopardy. In the series debut, Waverly is the target of a Thrush raid in U.N.C.L.E.'s New York headquarters (The Vulcan Affair). On another occasion, he is poisoned by Thrush and taken to a hospital controlled by the criminal organization (The Brain-Killer Affair).
At other times, Waverly thrusts himself into danger. He goes undercover in the middle of an assignment and ends up assisting Solo and Kuryakin (The Pieces of Fate Affair). On another occasion, while accompanying Kuryakin to a hospital in Washington, Waverly strikes a karate blow on a Thrush operative (The Deadly Decoy Affair). During the show's fourth season, he is captured along with Solo, Kuryakin and a U.K.-based U.N.C.L.E. agent, Brian Morton. It is Waverly who effects their escape, with a blade hidden in a carnation in his lapel (The Deep Six Affair).
Waverly also sometimes uses his brother-in-law, Professor Hemingway of YIT, as a consultant. Hemingway devises "exercises" to test the alertness of security at the New York headquarters (The Mad, MAD Tea Party Affair). Hemingway uses a secret entrance to reach Waverly's office, implying he is familiar with this entrance.
Waverly continued with the organization for some years after the end of the series. During the 1983 made-for-television film The Return of the Man From U.N.C.L.E., it is implied his death was a recent event. Leo G. Caroll made his final appearance as Waverly one week after The Man From U.N.C.L.E.'s cancellation in 1968. He appeared on "Rowan & Martin's Laugh-In," the series that replaced U.N.C.L.E. On Laugh-In, Carroll's Waverly is undercover once more, this time during the "party" sequence of the program. "Mr. Kuryakin, come quick," Waverly says into his U.N.C.L.E. communicator. "I think I've found Thrush headquarters at last." Thus, Waverly is a man of action to the last.