Baron Zemo () is the name of two supervillains appearing in American comic books published by Marvel Comics. Heinrich Zemo and his son Helmut Zemo have both been depicted as a major adversary of Captain America and the Avengers, as well as the leader of the Masters of Evil, a team comprising numerous villains in the Marvel Universe. In the 2021 radio drama podcast series Marvel's Wastelanders, two original incarnations of King Zemo (voiced by James Saito) are introduced as successors to Helmut Zemo as Dictators of the Wastelands: Herman Zemo (voiced by Ki Hong Lee) and Ash Morse (voiced by Sasha Lane). Publication history The initial published version of Baron Zemo was created by Stan Lee and Jack Kirby and was first seen in a flashback in The Avengers #4 (March 1964). The character did not actually appear in person and was not identified as Heinrich Zemo until The Avengers #6 (July 1964) and Sgt. Fury and His Howling Commandos #8 in the same month. Zemo was retroactively added into the history of Captain America upon the hero's reintroduction to the Silver Age two issues prior. The character subsequently appears in The Avengers #7 (Aug. 1964), #9-10 (October–November 1964), Tales of Suspense #60 (December 1964), and The Avengers #15 (April 1965), in which he is killed. Since then, Helmut Zemo has used the Baron Zemo title since Captain America #275. Harbin Zemo, the progenitor of the Zemo line was first seen, via flashback, in the Avengers/Thunderbolts limited series. The backstory of the 11 barons before Heinrich and Helmut was later touched upon in the limited series Thunderbolts Presents: Zemo – Born Better. So far it seems that every baron is succeeded by his son. According to Wendell Volker's notes, Harbin had other children before Hademar who did not survive to adulthood; Herbert had two sons who died of illness prior to Helmuth. Line of Barons in the Zemo family Marvel Universe Harbin Zemo – The 1st Baron Zemo who was around in 1480. Hademar Zemo – The 2nd Baron Zemo, son of Harbin Zemo and the greediest of the Zemos. He was killed by the guards (acting under Heller Zemo's orders) at his inauguration. Heller Zemo – The 3rd Baron Zemo, son of Hademar Zemo and the most progressive of the Zemos. Herbert Zemo – The 4th Baron Zemo, son of Heller Zemo. He was assassinated by his own