Real Name: Baron Heinrich Zemo
Occupation: Scientist, special operative for German intelligence, later would-be conqueror
Identity: Publicly known
Legal Status: Citizen of Germany, later citizen of an unidentified South American nation who was wanted through much of the world for war crimes
Other Aliases: None known
Place of Birth: Castle Zemo, Germany
Place of Death: Unidentified location in South America
Marital Status: Married
Known Relatives: Hilda Zemo (wife, deceased), Baron Helmut Zemo (son)
Group Affiliation: Founder and leader of the original Masters of Evil
Base of Operations: Germany, later the Amazon jungle
First Appearance: Avengers #4
Final Appearance: Avengers #15

History: Baron Heinrich Zemo was one of the most brilliant scientists of Nazi Germany, surpassed perhaps only by Arnim Zola. Zemo joined the National Socialist (Nazi) party early in its existence, and, after Hitler took power, offered his services to the government as a designer of new weapons for the military and for the intelligence services. Zemo's most notorious early in this area was his "death ray" gun that could disintegrate its targets. The "death ray" was actually a laser beam, which Zemo had discovered how to create decades before other scientists would reinvent the process. Sgt. Nick Fury and his squad of commandos invaded Zemo's castle in order to destroy the only existing "death ray" gun. Zemo blew up the castle, with the ray gun inside, rather than allow the commandos to capture it.

American and British newspapers had widely publicized Zemo's "death ray" and portrayed Zemo himself as a satanic figure; as a result, Zemo became one of the men most sought by Allied agents within Germany for capture or assassination. Zemo was even hated by the German people, for reason that remains unrevealed. Aware that he had become a target for attacks, and shaken by the invasion of his own castle, Zemo went into hiding along with his wife Hilda and their son Helmut, and even took to wearing a red hood to conceal his identity as he worked in the secret laboratories he built with the wealth given him by a grateful Hitler. Zemo's major project was now the development of "Adhesive X," and adhesive so strong that, once applied, it could be removed by any means then known to scientists. Adhesive X had tremendous military potential: enough of it, dropped of it, dropped from the air, could entrap a small army.

Wearing his hood, Zemo was working in one of his laboratories when Captain America broke into it. To prevent Zemo from turning over what was then his sole supply of Adhesive X to the Nazi government, Captain America hurled his shield at the vat containing the adhesive. The shield shattered the vat, whose contents poured over Zemo's head. Zemo escaped, but the hood was now permanently affixed to his head. Zemo could see through the hood's eyeholes, and it was thin enough to allow him to hear perfectly. The hood had no openings for the nose or mouth, but it was porous enough to allow Zemo to breathe. However, he could no longer eat, and for the rest of his life, Zemo had to take nourishment intravenously.

The shock of realizing what had happened to him worked a violent change in Zemo's personality. Although he remained as brilliant as ever, he was now driven by a nearly insane hatred of Captain America, the Allies, and even mankind in general. Zemo even began taking out his hostility on his wife and son. Zemo's hatred drove him to make radical new discoveries in the next few years. In collaboration with Arnim Zola, Zemo created powerful androids which, through means he developed on his own, he could shrink to a size small enough so that he could carry them in a box under one arm, and then could enlarge again to their full height of ten feet. Zemo recreated his disintegrator gun, although it was now on a smaller scale, and devised small rocket-powered aircraft.

Zemo no longer confined himself to scientific research. With Hitler's permission, Zemo led many missions of sabotage and terror against the Allies himself. Soon Zemo became the only rival to the Red Skull himself is such activities, and therefore, there was an ever present tension between the two. This tension built to a climax as World War II drew to its end in Europe in 1945. The Russians were marching towards Berlin, and both the Skull and Zemo knew that Germany's defeat was imminent. Captain America and his young partner Bucky had been assigned to guard Allied supply bases in Britain against last-ditch efforts at sabotage by Nazi agents. The Skull was enraged by his repeated defeats by Captain America and was determined that if the Third Reich must fall, then Captain America must die as well. As the second most powerful man in the Third Reich, the Red Skull ordered Zemo to go to London under the pretense of stealing an experimental drone plane from the Allied. The plane would, of course, be useless to Germany at this late point in the war. However, the Skull would see that word was leaked to Captain America that Zemo would try to steal the plane. The Skull ordered Zemo to kill Captain America and Bucky when they tried to stop him from stealing the plane. The Skull reasoned that he would win even if Zemo failed and was captured, for he would then be rid of his greatest rival. Zemo guessed the Skull's motive in selecting him for the mission, but welcomed it not only as an opportunity to kill Captain America, but also as his official means of leaving Germany before it fell to the Allies. After disposing of Captain America, Zemo planned to fly to South America, where he had already sent much of his wealth and scientific equipment. As Zemo made his preparations to leave for Britain, the Allies secretly airlifted Captain America into Berlin, where he had his final wartime battle with the Skull, and then was secretly flown back to England.

Upon landing in London, Captain America learned that Zemo would attempt to steal the plane, and he and Bucky arrived at the scene mere moments after Zemo did. One of Zemo's androids knocked out Bucky, and Zemo used a stun-ray on Captain America. He then dressed his unconscious foes in American army uniforms over their costumes, and had the androids lash them to the drone plane, where they would die in the unprotected flight to Berlin.

Decades later, Captain America and his fellow Avengers Hawkeye, Goliath, and the Black Panther, used a time machine invented by Doctor Doom to travel back in intangible form to this very day of Zemo's attempt on the drone plane to watch what happened. Due to outside influence, the Avengers materialized in the past in physical form. Zemo was astounded to be confronted by "another" Captain America, and theorized that there must be more than one. Captain America's self from the future and his fellow Avengers battled Zemo and his androids, but soon began fading once more into invisibility. But before Captain America's future self faded completely, he hurled his shield so as to server the bonds of the 1945 Captain American and Bucky. The 1945 Captain America awoke in time to seethe shield, but he did not see his future self, Zemo, having discovered that the drone plane was booby-trapped while examining it, then launched the plane, pretending that the Third Reich must have it. Captain America and Bucky raced after it on a motorcycle and leapt toward it. Captain America could not reach it, but Bucky did. As Captain America plunged towards the sea below, he warned Bucky to let go, because the plane might be booby-trapped. Seconds, after Bucky spotted the bomb on the plane, it exploded, killing Bucky. The icy waters below and the "Super-Soldier" serum in his body sent Captain America into suspended animation for decades. The triumphant Zemo flew to an undisclosed location in a South American jungle, where he spent the next decades in hiding, and the observing Avengers returned to their own time. Zemo had left his wife and son behind in Germany.

Zemo was certain that he had killed the Captain America who had always fought him in the past, and so he was undisturbed by news reports about other Captain Americas over the following years. Zemo spent the next decades working on his means for conquering the world: a gigantic satellite bearing a series of mirrors with which he could convert solar energy into a "death ray" capable of wiping out entire cities.

But then in later years Zemo learned from a newspaper of the return of the original Captain America, and realized from what Captain America told the press that he was the one Zemo had fought and thought he had killed. Infuriated, Zemo determined to kill Captain America. To this end, he recruited the second Black Knight, the Melter, and the Radioactive Man, who together became known as Zemo's Masters of Evil, to kill Captain America's new partners, the Avengers, so that they could not protect him from Zemo's vengeance. These first three Masters of Evil failed, as did Zemo in his effort to kill his revived foe. Zemo next recruited the Enchantress and Executioner, and later used a special radiation treatment to transform Simon Williams into the superhumanly strong Wonder Man, so that he could help defeat the Avengers. Zemo still met with failure against the Avengers. Next Zemo entered an alliance with Immortus to fight the Avengers.

Finally, in an all-out effort, Zemo had Captain America's friend Rick Jones captured and brought to his South America base, while he had the second Black Knight, the Melter, the Enchantress, and the Executioner a full-scale attack on the Avengers. Captain America flew to Zemo's base and rescued Jones. Zemo then led his men in a charge against Captain America, who used his shield to create a landslide that separated himself and Zemo from Zemo's men. Zemo aimed his death ray directly at Captain America, who used his shield to reflect strong sunlight into Zemo's eyes, temporarily blinding Zemo fired wildly, causing another landslide, which killed him. Captain America buried Zemo's body himself.

After Baron Zemo's death his pilot impersonated him and put into execution Zemo's scheme to blackmail the world into submission through an orbiting death-ray device. Captain America, the Black Panther, and the late S.H.I.E.L.D. agent Sharon Carter thwarted the imposter's scheme. The pilot was killed by his own men after his unmasking by Captain America.

His son Helmut, who, as current Baron Zemo, has unsuccessfully sought vengeance on Captain America for his father's death, took on Heinrich Zemo's title and scientific heritage. Helmut Zemo is middle-aged and it is as yet unknown whether he himself has any offspring.

Height: 5 ft. 9 in.
Weight: 180 lbs.
Eyes: Blue
Hair: Grey-black

Strength Level: In his prime Baron Heinrich Zemo possessed the normal human strength of a man of his age, height, and build who engaged in moderate regular exercise. It is believed that Arnim Zola supplied him with serums that enabled him to retain much of his strength and physical vitality into his old age.

Known Superhuman Powers: None

Abilities: Baron Heinrich Zemo was a brilliant scientific genius who made great advances in the field of lasers technology, the development of adhesives, genetic manipulation, and the creation of androids.

During his decades his in South America Zemo trained himself in methods of unarmed combat, including karate, and he remained a formidable master of these skills to the end of his life.

Weapons: Zemo carried a disintegrator gun as a hand weapon. The most infamous of his weapons, however, was "Adhesive X" which can only be removed by means of a chemical formulated by the Trapster.