Artemis Hardbroom (Nephew)
Deputy Headmistress and Potions Teacher
Constance Hardbroom (Hecate Hardbroom in the 2017 series) is the fearsome deputy headmistress of Miss Cackle's Academy and the clear power behind the throne. She is Mildred's form mistress in first form and through various combinations of events continues to be her form mistress throughout the series. Tall, bony and sour-faced, she strikes fear into the pupils' hearts. "HB", as the girls refer to her, seems to have a particular resentment of Mildred. Miss Hardbroom frequently praises and rewards Ethel Hallow, and frequently rebukes Mildred in front of the other students. It is Miss Hardbroom who gives Mildred the title of "the worst witch in the school".
BooksMiss Hardbroom grew up in a strict household; she never had a birthday cake and was only given one birthday present, usually something useful like a spellbook. 
Miss Hardbroom has a beautiful, sleek black cat called Morgana.Miss Hardbroom owned her magic broomstick for twenty-five years, until Mildred accidentally breaks it when she jumps on Miss Hardbroom having mistaken her for an evil witch.
1998 TV Series
Miss Hardbroom is a representative of The Cauldron Club, and she was in the club herself at Weirdsister College.  The Cauldron Club is for high-achieving students to further their studies and interests.
Miss Hardbroom also attended Witch Training College, where Mistress Hecketty Broomhead was her personal tutor; she taught Miss Hardbroom "Everything she knows" (including how to appear from thin air). Miss Hardbroom encounters Mistress Broomhead twice at Cackle's, first as a Witches' Guild inspector, and then as acting Headmistress.
In her first year, Mildred saves Cackle's Academy from Agatha Cackle and her coven, earning her first smile from Miss Hardroom. In Mildred's second year, Mildred saves Miss Hardbroom's life after Miss Hardbroom slips over, is knocked unconscious, and inadvertently set adrift on a boat; Miss Hardbroom is grateful for this.
Two episodes in the TV series give particular insight into Miss Hardbroom's character: The Inspector Calls, and The Millennium Bug, both in season two. In The Inspector Calls, we meet Hecate Broomhead and discover that Miss Hardbroom is afraid of her, one of the very few times she shows visible fear. In The Millennium Bug, Miss Hardbroom threatens to resign when Mr Hallow decides to sell the school- she can "only dance to one tune" and doesn't want to teach in the new school. This leads to a conversation between her and Mildred, who ends up saving the school.
Miss Hardbroom states that she "sleeps most nights, six hours at the weekend!" She uses Wide-Awake Potion to keep herself going, and is often on the lookout for students sneaking around at night. Miss Hardbroom also owns a Magic Mirror, which is kept in the staffroom.
When Mildred starts at Weirdsister College, Miss Hardbroom is summoned by magic to test Mildred (and tell her off), to see if she was strong enough to enter Weirdsister as a student. Mildred passed and Miss Hardbroom wished her luck, and a smile before returning to Cackle's.
The New Worst Witch
2017 TV Series
Miss Hardbroom is said to have had an austere upbringing. She attended Cackle's Academy as a girl; according to her student record (seen in Finding Joy) her best subject was Potions, but she needed to improve in PE. Her hobbies are listed as Advanced Potions, The Art of Flying, and Materialization Practice, and she was Potions competition winner 3 years running, as well as getting an award for Best New Potion and a scholarship to Potions Summer Camp. She completed her education at Cackle's, and went on to further qualifications and training. Mildred’s room at Cackle's was previously Hecate’s when she was a student at the academy; Indigo Moon refers to it as ‘the one with the bats’. When she is introduced in Selection Day, Miss Hardbroom believes that witchcraft is in decline. Because of this, she favours the talented Hallow sisters, Ethel and Esmerelda, and anticipates the termination of Mildred's trial at Cackle's. She claims that she does not hate Mildred; she simply believes the academy is "no place for [Mildred]".
Whilst she terrifies her students and is strict and severe, it is clear that she always acts in what she thinks is in the best interests of the academy. It is her who subtly double-crosses Agatha Cackle in the first episode by finding a loophole in the Witches' Code that Mildred can exploit. In Out of Bounds, when Agatha escapes her banishment, Miss Hardbroom puts protective enchantments on the castle, so that no one can get in unless they are invited, and students are banned from leaving the school grounds.
In The Worst Headmistress, Miss Hardbroom hints to Maud that Miss Cackle is trapped in the painting in the Headmistress' office. After the students are unable to rescue Miss Cackle, Miss Hardbroom tries to summon Miss Cackle herself, but her magic sets off Miss Gullet’s alarm, and Miss Gullet and Agatha trap Miss Hardbroom in the painting as well. When Agatha tries to destroy the school, all the students chant together to stop her spell, and this also changes Esmerelda Hallow, the teachers, and the grand wizard back into themselves, and Agatha and Miss Gullet end up trapped in a photograph by Miss Cackle. Miss Hardbroom also showed signs of mellowing out towards Mildred by awarding her 51% on her final exams despite the latter crashing into a tree.
In Mildred's second year, when it is revealed that Mildred is actually from a witching family, Miss Hardbroom comments to Mildred that her being from a witching family changes things- she will have to be harder on her than ever!
In Mildred's Third year, it is revealed that Miss Hardbroom's real name is Joy, who was a talented young witch who thought she knew better than other witches. She ignored the witches’ code and was drawn to the non-magical world, and things like ice cream, music and dancing. Joy became friends with Indigo Moon, a non-magical girl who believed in magic, and could therefore see through the invisibility spells that hide witches and magic from the rest of the world. But when the teachers at Cackle’s found out, Joy was confined to the Academy and grounds.
Joy stole a wishing star and gave Indigo magical powers so they could be together, but Indigo got carried away with the magic, and she turned to stone. Joy dedicated herself to following the witches’ code, cut herself off from her witch friends, went by her middle name, Hecate, and now 30 years later, She is Miss Hardbroom, and has remained confined to the Academy all that time, apparently of her own choice. At the end of the year, Miss Hardbroom considers leaving Cackle's after the events surrounding Indigo Moon, and Miss Cackle removes the confinement spell so she can leave. However, Miss Bat encourages Hecate to stay at the Academy, to make things up with Indigo and to become her teacher.
Miss Hardbroom is tall, thin and bony with waist-length black hair which she keeps "scragged into such a tight knot that her forehead looked quite stretched". Miss Hardbroom keeps her hair tied up in a tight bun at all times, except for the Halloween celebrations, as it’s tradition that all the witches wear their hair down for Halloween. Mildred remarks that she doesn't look half as frightening when her hair is down. In the TV series she also wears her hair down at Miss Drill’s investiture and sometimes at night.
In the 1986 film Miss Hardbroom is portrayed by Diana Rigg. In the 1998 TV series she is portrayed by Kate Duchêne, and in The New Worst Witch by Caroline O'Neill. In the 2017 CBBC series she is called Miss Hecate Hardbroom and played by Raquel Cassidy.
Personality and Traits
As the Deputy Headmistress, Miss Hardbroom seems to be the real power behind the throne at Cackle's Academy - it is her who mostly succeeds in imposing her will on everyone by means of frowns, or shouts, or simply talking a blue streak until everyone gives into her.
Miss Hardbroom is a stickler for standards and tradition, as well as a firm believer in strong discipline. Due to her natural capacity for strictness and intimidation, she had been described to be able to reduce any pupil to a gibbering heap with just one word. In fact, it is her who gives Mildred the infamous title of "the worst witch in the school". She is also a "staunch traditionalist" - as seen in Sorcery and Chips, she views computers and all other modern technology as infernal machines. It still must be noted, though, that despite being a strict traditional disciplinarian, Miss Hardbroom truly cared for each and everyone of her students, and if need be, she would be the first - apart from Miss Cackle - to spring to their defense.
Like any other person, Miss Hardbroom does have her weaknesses: as demonstrated by her temper tantrums in The Millennium Bug (mentioned only) and Better Dead than Co-ed, she could be immature when she is angry or upset, to the extent where she would raise her voice to the point of shouting, and finally disappear to be by herself - at least, until Miss Cackle or Mildred was able to find her. She was also actually afraid of one witch, Mistress Hecate Broomhead, who had once been her personal tutor. Hence, she found out about about Mistress Broomhead's inspection of Cackle's Academy, she actually sat down and warned her fellow staff to be on their guard, and even went as far as to attempt to conceal Mildred's very presence from Mistress Broomhead.
In spite of all this, Miss Hardbroom did have a soft kind side, and knew when to give credit where it was due. For instance, in Double, Double, Toil and Trouble, she sincerely thanked Mildred for saving the academy from Miss Cackle's evil twin sister, Agatha, to which Mildred remarked to her friends - "You know, sometimes I don't think she's as bad as we think she is". She also restored Mildred's hair to its rightful length in The Worst Witch Saves The Day.
As seen in The Inspector Calls, she could be capable of being amused by wholly unexpected revelations, such as Mistress Broomhead having been an utter juvenile delinquent worse than Mildred ever was.
Last but not least, Miss Hardbroom was a true lover of rare talents - in The Uninvited, upon the realisation that Mildred possessed a unique magical talent (bringing drawings to life) that she had never ever seen before, she actually changed her mind about Mildred's suspension, and even saw to it that Mildred was able to remain at Cackle's Academy as Head Girl. When she encountered Mildred during the Weirdsister College's initiation ceremony in The All Seeing Eye, and verified for herself on how much the young witch had truly matured, Miss Hardbroom gifted her with a rare smile and even wished her good luck, which also proves that she was a teacher who was genuinely happy to see her former students continue to excel at higher levels of magical education, no matter what previous disagreements she might have had with them.
Miss Hardbroom's description on the BBC site reads: "Deputy head Miss Hardbroom is tough but fair - in her own mind at least. She’s had an austere upbringing and is actually rather lonely and (some might say) repressed. For her, witchcraft is all about strict traditions and sacrifice, and demands high levels of discipline, commitment and hard work from her students. Miss Hardbroom is genuinely concerned that one day Mildred’s chaotic magical abilities will cause a disaster - which is why she is particularly hard on her." 
Miss Hardbroom is an extremely powerful witch, and her primary method of casting spells was through her fingers: pointing with the index and little fingers. Her most notable ability was to appear out of nowhere, and according to the 1998 TV series, she was the only witch (aside from Hecate Broomhead) who was shown to possess this ability, although in the 2017 TV series, the other teachers were shown to be capable of this as well. Hence, the students often say that one never knew if she is truly gone, or if she was still there in an invisible state. She herself does nothing to dispel this.
Miss Hardbroom also demonstrated the ability to accurately identify potions simply by smelling them, and once claimed that she scored "the best results of virtually every potion teacher in the country", which implies that she is a skillful teacher who knew her subject well.
Due to Miss Hardbroom's formidable powers, it is often left up to her to save the day when situations get out of hand. When Miss Cackle's evil sister, Agatha, and her sidekicks tried to take over the school, Agatha stated that "Hardbroom is the really dangerous one" and must be dealt with first. During an unexpected honest conversation between Miss Hardbroom and Mildred, the former explained that her ability to appear out of nowhere was actually "a professional secret". Such instances testify that Miss Hardbroom was well-known and feared by the adult witch community.
Miss Hardbroom has an intimate relationship with her Headmistress, Miss Cackle, which actually resembles that of a mother-daughter relationship more than a professional one. In fact, it could be said Miss Cackle was the only other staff member whom Miss Hardbroom was on decent terms with, for she was inclined to be critical of the other teachers - she viewed Miss Bat as incompetent and irresponsible, and felt Miss Drill was always too indulgent towards the students for their own good.
It was often up to Miss Cackle to prevent her Deputy from going overboard, for despite her strict traditional nature, Miss Hardbroom truly respected the Headmistress, and whatever her personal feelings may be, once Miss Cackle had made-up her mind on a decision, she would not protest. For instance, during Mildred's second year, on Miss Cackle's suggestion, a severely overworked Miss Hardbroom accompanied the second-year students on their trip to Algernon Rowan-Webb's riverside home.
However, Miss Hardbroom would resort to measures as drastic as resignation if she genuinely feels that certain decisions of Miss Cackle's were utterly wrong - in The Millennium Bug, when Mr. Hallow wanted to sell the castle to Amanda Honeydew, Miss Cackle actually had to chase Miss Hardbroom down the hall, begging her to reconsider her decision to resign. Later on, during her unexpected yet honest conversation with Mildred over her resignation, Miss Hardbroom confessed that it was because she "only knew one tune, and cannot dance to another", which shows that though she would usually relent to Miss Cackle's decisions, there were still certain personal boundaries that she was adamant in not breaking.
Miss PentangleIn The Worst Witch Saves the Day, it is revealed that Miss Hardbroom is good friends with Miss Pentangle (they especially like playing chess together). 
In the 2017 TV Series, Miss Hardbroom and Miss Pentangle used to be friends, and it is implied that they went to school together. Miss Pentangle was popular in school, while Miss Hardbroom was tall, gangly, and not as popular. Miss Hardbroom thought Miss Pentangle wouldn’t want to be friends with someone like her, but Miss Pentangle actually considered Miss Hardbroom her best friend. They eventually make up (thanks to Mildred) with a hug.
The following year, Pippa returns to Cackle's as replacement head when Miss Cackle is removed as headmistress, but Hecate is not happy about Pippa taking Miss Cackle's place. She also thinks Pippa is being to showy, and this leads to arguments; Hecate thinks that Pippa is always trying to be better then her. Pippa admits to Mildred that "Miss Hardbroom and I agree to disagree on many things." However, Pippa admits to Hecate that she never wanted to be better than her, she wanted to be like her, because she’s “The witchiest witch I ever knew, and always will be,” and farewells her with a kiss.
Miss Hardbroom hosts a strong contempt for every creature of the male species. When "The Witchy Hour" radio show was hosted at Cackles', DJ Icy Stevens seemed to fall in love with her at first sight, and she appeared to reciprocate, but she simply appreciated his admiration. When he invited her to go away on a romantic holiday and put his hand on her arm, she immediately rebuffed him. She does show a level of respect for both Mr Blossoms however.
Miss Hardbroom took a particular dislike to Mildred at first sight - it was Miss Hardbroom who titled Mildred as "the worst witch in the school", and this dislike used to be quite mutual. However, over their years together as teacher and student, both grudgingly came to learn - though never admitted - that the other has her strong points, which results in a kind of love-hate relationship. In fact, during Mildred's and Miss Hardbroom's heart-to-heart conversation in The Millennium Bug, Mildred revealed that what she truly hated about her teacher was her ability to appear out of nowhere, while Miss Hardbroom in turn confessed she was constantly exasperated with Mildred's bad habits, impulsiveness, and uncanny tendency of always saving the school from catastrophes.
Despite this, it still must be noted that Miss Hardbroom has absolutely no qualms with rebuking Mildred in front of the other students, and makes no secret of her preference for Ethel Hallow. In The Uninvited, Miss Hardbroom was, for once, utterly astonished yet impressed by Mildred's newly-developed magical talent to bring her drawings to life, as she had never seen anything like it before. This, coupled with her gratitude towards Mildred for saving the entire school from The Uninvited (the evil witch from Sleeping Beauty), changed her mind regarding Mildred's suspension - she magically stuck Mildred's and Jadu's expulsion letters to Ethel's fingers, and celebrated along with the others when Mildred was made Head Girl.
After Mildred's graduation from Cackle's Academy, she encountered Miss Hardbroom again during the Weirdsister College's initiation ceremony. While Miss Hardbroom initially expressed skepticism as to whether Mildred would not mess things up at her new college, the young witch openly and sincerely acknowledged her previous flaws, but also reminded her former teacher that she was "old enough to make her own decisions", and live with whatever consequences those decisions resulted in. With that, Miss Hardbroom was convinced that Mildred had truly matured for the better, and after wishing her good luck with a rare smile, she disappeared.
In the 2017 episode Tabby, Miss Hardbroom says that she doesn't hate Mildred, but rather does not believe that Mildred belongs at Cackle's and does not want her to be a bad influence on Maud Spellbody. She does not expect Mildred's trial to last very long. In Pond Life, Miss Hardbroom gives Mildred an ultimatum: if she cannot perform a simple frog transformation spell, she will end her trial. Mildred fails the test, but Miss Bat sticks up for Mildred.
Miss Hardbroom seems to warm towards Mildred at the end of the episode Spelling Bee after Mildred helps mend the friendship between Miss Hardbroom and Miss Pentangle. In The Worst Headmistress, Miss Hardbroom enlists Mildred's help in an attempt to save Miss Cackle from a painting, as only Mildred's magic will not set off an alarm. When Mildred fails, Miss Hardbroom consoles her - she tells her it is not her fault as she is too young to perform such a complex spell. After the school has been saved and the students are undergoing their end of term tests, Mildred crashes into a tree in a broomstick test. Miss Hardbroom says that most examiners would fail her, but says she is not most examiners. She gives Mildred a grade so that her marks average at 51% - Mildred has just passed and can come back for a second year at Cackle's.
In Mildred's third year, it is revealed that, as a girl, Miss Hardbroom made a similar mistake to Mildred, giving magical powers to a non-magical person. It is implied that Miss Hardbroom may have convinced Miss Cackle to let Mildred stay at the Academy after this incident. The young Miss Hardbroom looked very similar to Mildred, plaits and all, suggesting that Hecate sees her younger self in Mildred, and doesn't want Mildred to make the same mistakes she did.
- Miss Hardbroom would be the most popular character in The Worst Witch, particularly her TV series portrayal by Kate Duchene.
- Fans commonly refer to Miss Hardbroom by her nickname, HB (also spelt H.B.).
- Miss Hardbroom is often compared to Professor Severus Snape from Harry Potter . They are both tall and thin, wear black and have black hair, as well as both being strict potions teachers. Miss Hardbroom is also considered to be like Professor McGonagall, the Deputy head of Harry Potter's Hogwarts, in that they are both strict, but are caring underneath.
- In the episode Art Wars, Miss Hardbroom states that her favourite colour is black.
- Miss Hardbroom's age is never mentioned, though she mentions that she is a Capricorn in The Unfairground. According to The Worst Witch Magazine, though, she is a Scorpio. In Bad Magic, Miss Hardbroom states that the incident with Indigo Moon happened 30 years ago, which would make Miss Hardbroom aged in her forties.
- Despite her claims that she dislikes modern technology, Hardbroom was more then capable of operating the radio broadcast unit in "The Witchy Hour" with just a brief glance. Of course, it is possible for people who dislike certain things to nonetheless be quite capable of using them.
- Miss Hardbroom’s name in other languages:
French TV: Mademoiselle (Mlle) Constance Harebours (or Arebours), It means "countdown".
French book: Mademoiselle (Mlle) Bâtonsec; Nickname: “La mere bat´sec”. ‘Baton’ means ‘Stick’, referencing the ‘Broom’ part of her name.
German: Frau Constanze Harschmann; Nickname: “HM” - Mrs Constanze Harshman
Dutch: Heks Constance Hakblok- Witch Constance Chopblock
Latin-American: Miss Ogrum- a pun on "ogro" which means "ogre" in Spanish.
Czech: Slečna Constance Metlová; Nickname: Metla
- In the 2017 TV Series, Miss Hardbroom's name is given not as Constance but as Hecate, the same as Mistress Broomhead, her former tutor who appears in the 1998 TV Series. In Greek mythology, Hecate is the goddess of magic, witchcraft and necromancy.
- Raquel Cassidy on playing Miss Hardbroom:
“From the books, she’s very tall, and she’s very severe, and she wants the best for the girls, but she believes that the way the way to do that is to be very, very strict. I’d…(laughs)… Is there much of me in Miss Hardbroom? Yeah, there’s plenty of me in Miss Hardbroom, there is. There is a massive invitation to play… with her, and I can’t seem to help myself.” 
- The Worst Witch (Book)
- The Worst Witch Strikes Again
- A Bad Spell For The Worst Witch
- The Worst Witch All At Sea
- The Worst Witch Saves The Day
- The Worst Witch To The Rescue
- The Worst Witch and the Wishing Star
- First Prize for the Worst Witch
- The Worst Witch (1998 TV Series)
- Weirdsister College (TV Series) (The All Seeing Eye)
- The New Worst Witch
- The Worst Witch (1986 Film)
- The Worst Witch (2017 TV Series)