Hydra has plagued the Marvel Universe since the Marvel Age of comics. It is one of its most pervasive and vile criminal organizations. While there is an ancient incarnation of the organization, the Hydra we know started in Nazi Germany with Baron Strucker and has stuck around to threaten free peoples into the modern-day. It is an organization of hate, violence, and conquest
Several people have led Hydra in the past, and each one did so with the blackest of hearts. However, some of these cruel souls have done so with more success than others. Each one accomplished their goals through bloodshed and subjugation.
10 Doctor Faustus
Doctor Faustus is a master of the mind who can use words, images, and whatever else it takes to bend someone to his will. He first came on the scene when treating Captain America for his PTSD suffered from World War II. Faustus attempted to coerce Steve into committing suicide. Steve broke free of his influence, but Faustus would plague him for years to come, often working with the Red Skull. He helped break Sharon Carter and forced her to kill Captain America at the end of the Superhero Civil War. Faustus became a head of Hydra when its newest iteration took over the United States.
9 Arnim Zola
Arnim Zola is a geneticist who has been a part of Hydra since World War II. He helped create the first Master Man and even designed robots for Baron Heinrich Zemo. He has stuck around in a robotic body and has often been found working with the Red Skull since then. One of his more recent atrocities was the creation of Dimension Z, a realm controlled entirely by Zola and populated with monsters and people to subjugate. Captain America was caught in Dimension Z for over a decade and was able to overthrow Zemo with the help of Sharon Carter and the new Nomad before escaping.
8 Madame Hydra
There have been several Madame Hydra's over the years, each with her one frightening wrap sheet. However, the one who proved the most effective is Elisa Sinclair, who was created by the sentient Cosmic Cube known as Kobik. Elisa was a close friend of Sarah Rogers and helped corrupt her and her boy, Steve, to become members of Hydra. This led that alternate timeline Steve Rogers to become the one who took over Hydra and then the United States in Secret Empire (2017).
That said special props to Viper and the Contessa, who were vicious and deadly Madame Hydra's as well.
7 Baron Heinrich Zemo
Credit must be given to the man who killed Captain America and Bucky Barnes. While this "death" didn't quite stick, Heinrich Zemo took America's greatest hero off the table for decades, and he put Buky in the position that he would be taken and brainwashed into becoming the deadly Winter Soldier. He would die in a fight with the Avengers decades later, but his son would take up the mantle of Baron Zemo.
6 Sin
Sinthea Schmidt, the Daughter of the Red Skull, truly lived up to her father's legacy. She was saved by S.H.I.E.L.D. and brainwashed to forget her father, but Crossbones found Sin and reminded her who she was. Since then, she has been on a rampage, the crown jewel of which was summoning Asgardian Cul, God of Fear and brother of Odin, to Earth along with eight magic hammers. She also orchestrated an American Blitzkrieg to sew chaos alongside the coming of Cul. During this time, she seemed to kill Bucky Barnes, who was Captain America at the time, but he survived and returned to his career as the Winter Soldier. Eventually, the heroes of Earth were able to push back Cul and the American Blitzkrieg of Sin. Since then, Sin has been a mainstay of Hydra's high council through its conquest of America.
5 Baron Helmut Zemo
Baron Helmut Zemo became a fixture of Hydra in more recent years. After taking up his father's legacy, he battled Captain America on several occasions, founded the Thunderbolts--which brought him to the brink of world domination--and later killed the Grandmaster himself in single combat. When Bucky Barnes surfaced as the new Captain America, Helmut orchestrated the exposure of Bucky's past as the Winter Soldier. He took the Kraken's place as leader of Hydra and ran the rogue nation of Begalia. When Steve Rogers became part of Hydra, he considered Helmut Zemo his closest friend and second in command.
4 The Gorgon
The Gorgon may be the deadliest warrior to have ever led Hydra. While other leaders of Hydra prefer to have their underlings accomplish tasks, the Gorgon likes to handle his foes personally. He was the one who had Wolverine brainwashed during the "Enemy of the State" story, and he headed the attempted union between Hydra, the Hand, and A.I.M.
He later became a member of Hydra's high council, and he awakened the massive sleeping dragon beneath Madripoor. He was gone from Hydra before it took over the United States and has accepted his mutant birthright on Krakoa.
3 Baron Wolfgang Von Strucker
In a way, everything Hydra has done is on the head of Baron Wolfgang Von Strucker, as he is the founder of it all. He organized Hydra during World War II and has managed to stay alive in one way or another in the decades since then. He held the reigns of Hydra until recent years, and he even helped the organization infiltrate and corrupt S.H.I.E.L.D. He was killed by Nick Fury Sr., but he has since come back through unknown means.
2 Red Skull
Captain's America deadliest enemy and perhaps the most personally vile rogue to ever live. He is a true believer in the Nazi cause. He killed Roscoe Simmons, a man who briefly tried to be Captain America when Steve Rogers was Nomad. He unleashed the "Red Death" virus that killed countless around Mount Rushmore. He orchestrated the death of Captain America with Doctor Faustus after the Superhero Civil War, but he was killed by Steve Rogers when he was resurrected. Since then, a clone of the Red Skull stole the brain of the then-deceased Charles Xavier, used his telepathic powers to unleash the Axis event, and used Kobik to turn Steve Rogers into Hydra's most committed member. The clone was killed by the evil Steve Rogers when he took control of Hydra.
1 Captain America
The greatest Hydra leader is obviously the one who won, right? The evil Steve Rogers used Hydra's assets to take control of the country, orchestrate a Chitauri invasion of Earth to cement control, wiped out Las Vegas, and killed Rick Jones. He went to war with Inhumans, the mutants, and Wakanda. He was only stopped when the true Steve Rogers returned, and he was seemingly killed when Alexa Lukin broke him out of prison. However, none of this stopped him from tarnishing the legacy of Captain America.