Harry Potter's nemesis, Voldemort, amplified his power by enlisting believers in his cause to commit terror and mayhem on his behalf. These Death Eaters were usually from the wizarding world's pureblood upper crust. While some of the Death Eaters were dizzying strategists, pulling off complex plans in service of their Dark Lord, others were just plain bad at their evil jobs.
Here are Voldemorts 10 most loyal Death Eaters, ranked by intelligence.
Antonin Dolohov
Antonin Dolohov was a pretty dim bulb. Sure, he could cast a powerful curse, but Dolohov didn't manage to evade prison after Voldemort's first fall. He participated in the mass Azkaban breakout but promptly wound up behind bars again after his involvement in the battle with Harry Potter and friends in the Department of Mysteries.
After breaking out again, he tried to track and confront Harry Potter and some friends, only to end up stunned and mind-wiped by Hermione Granger. Although he killed many good witches and wizards, including fan-favorite Remus Lupin, with Dolohov's record of bumbling, it's best to chalk that up to brute force over smarts.
Crabbe And Goyle, Sr.
Viewers and readers weren't treated to much discussion of Crabbe and Goyle's parents, but the odds are good that the apples didn't fall too far from the dimwitted tree.
Lucius Malfoy
The best thing about Lucius' head is his (admittedly fantastic) hair. If a problem can be solved with money or connections, Lucius is your man. If it comes to creativity, leadership, or cunning... Well, it's a good thing the man married Narcissa Black. Most of Lucius' initiatives for Voldemort backfired or were half-baked, to begin with - planting Voldemort's diary on Ginny Weasley was a very odd choice - and when the Malfoy name started to carry less sway, Lucius was utterly adrift.
Narcissa looked for out-of-the-box solutions and ended up tapping many unlikely allies - such as Snape and even Harry Potter - to get the family back our of hot water, but Lucius stuck to the privilege playbook long after it stopped working for him.
Bellatrix Lestrange
Bellatrix Lestrange was one of Voldemort's most powerful assets. Her blend of volatility and true, fervent love for Voldemort, not to mention her nasty arsenal of Unforgivables, made her formidable. In lucid moments, Bellatrix was very smart - teaching Occlumency to Draco, defeating imposing foes like Aurors Tonks and Kingsley Shacklebolt, making use of her surroundings to kill Sirius Black.
But many, many moments were not so lucid for her. Bellatrix's damage from Azkaban and over-fervent devotion left her liable to blurt out important strategies and secrets, and bungle missions. Before Azkaban, Bellatrix may have topped the list of smartest Death Eaters, but her capacities diminished before her true love rose again.
Walden Macnair
The Ministry of Magic's creature executioner might not have chosen the most innocent-seeming occupation after his early affiliation with Voldemort, but Macnair managed to stay out of jail before Voldemort rose again and make a living doing what he loved.
After Voldemort returned, Macnair proved surprisingly smooth-tongued, persuading the giants to join Voldemort's rise. He was jailed after the Death Eater raid on the Department of Mysteries but managed to break out again. All in all, Macnair was reasonably clever.
Draco Malfoy
Draco Malfoy was railroaded into taking the Dark Mark due to his father's missteps. The surprising effectiveness of a plan concocted while he was a terrified teen is a testament to his intelligence.
Thinking to fix a broken Vanishing Cabinet was a stroke of insight, and actually pulling it off and creating a route into the notoriously secure Hogwarts School must have been quite difficult. Sure, Dumbledore and Snape were onto him, but Draco's initiative and surprising handyman skills are enough to vault him into the middle ranks of a rather dim lot.
Peter Pettigrew
Peter Pettigrew was allegedly stupider than all of his school friends, but he still managed to pull off the extremely difficult Animagus transformation as a schoolboy. He also fooled many sharp members of the Order of the Phoenix as a double agent in the first conflict with Voldemort.
His plot to frame Sirius Black was audacious, surprisingly clever, and very committed; the sacrifice of a single finger really sold his story and landed Black in jail for a decade while Pettigrew went scot-free. Pettigrew's unprepossessing appearance and deferential manner might seem like they held him back, but it's noteworthy that he avoided the anger and punishments most Death Eaters in close contact with Voldemort ended up suffering. Perhaps Pettigrew was smart to snivel and lay low.
Corban Yaxley
Corban Yaxley is the rare Death Eater with an eye for subtlety, indicating his smarts. Yaxley, a spy in the Ministry of Magic, managed to place the Imperius Curse on the Head of Magical Law Enforcement, Pius Thicknesse. Yaxley was able to puppet Thicknesse through the Ministry to place all of the other major department heads under Imperius, clearing the way for Voldemort to murder sitting Minister of Magic Rufus Scrimgeour.
Yaxley then arranged to install Thicknesse as Minister of Magic, and Yaxley ran the administrative wing of Voldemort's fascist state through his Imperiused figurehead. Yaxley was also able to recover his wits quickly enough to break a jinx and take advantage of Harry Potter and Hermione Granger's break-in of the Ministry. Through his quick thinking, Yaxley was able to expose the headquarters of the Order of the Phoenix at Grimmauld Place. All in all, Yaxley was an effective Death Eater.
Barty Crouch, Jr.
It takes a lot of smarts to pull off a long con. It takes even more intelligence to work around a lack of resources. Barty Crouch, Jr. spent years trapped in his house and under the influence of the mind-numbing Imperius curse, but he still cobbled together the wherewithal to find or brew a year-long supply of the restricted Polyjuice Potion.
He then captured a notoriously paranoid Auror who was still spry enough to be an active part of the war effort, and convincingly impersonate that Auror during a high-visibility yearlong sporting event and teaching gig with colleagues who knew Auror Moody personally. Any way you slice it, Barty Crouch, Jr. was surprisingly sharp for a guy who can't keep his tongue in his mouth.
Severus Snape
Snape knew how to bottle glory, stopper dreams - and fool a suspicious Dark Lord and his many plotting underlings. Snape might not have been loyal to Voldemort, but he was the picture of fidelity to his own late-in-life principles. Snape was smart enough to pull off a dangerous double-agent act, all while inventing spells, advancing potions research, and holding down a full-time job - all while under constant observation from the Death Eaters' children.
Snape's careful planning saved the day many times. If this list spoke to emotional intelligence, there'd be a different conclusion - terrorizing eleven-year-olds and staying hung up on your high school crush for literal decades are sure choices - but Snape was definitely the smartest Death Eater.