When first he appears Childermass is simply Norrell's servant and man of business. His precise standing and duties within Mr. Norrell's household are not clear[2, 30], but originally he carries out his master's instructions and is particularly instrumental in suppressing the activities of other magicians. For example, it is Childermass who oversees the pact by which Norrell obliges the Learned Society of York Magicians to disband [2,3], and who later prevents John Segundus from founding a school of magic.As the story progresses however Childermass emerges as a person of greater independence. He admits to Vinculus that he allows himself a good deal of latitude in precisely how he carries out his master's commands. He openly criticizes Norrell's overweening behaviour and jealousy of other magicians, and demonstrates sympathy to those, such as Jonathan Strange, with whom Norrell is at odds[48, 50]. It also gradually becomes clear that Childermass is himself a magician of some skill, particularly happy in prognostication[21, 46, 48]. He remains loyal to his master however, even saving him at risk to his own life when Lady Pole attempts to assassinate him; but eventually, after a final breach with Norrell caused by the latter's choice of Henry Lascelles as his right hand man, Childermass leaves his service. He is instrumental in freeing Lady Pole from enchantment, and briefly meets John Uskglass (unfortunately without recognizing him and, as the memory is magically erased, without afterwards being able to recall the incident). After this he joins forces with Vinculus and by the end of the book, following the disappearance of both Strange and Norrell, is actively promoting the spread of practical magic. He does this by travelling the country with Vinculus and attempting to explain the meaning of the writing the Raven King has inscribed on the latter's body.
Biographical details about John Childermass which occur at various points in the book reveal he was by birth a Yorkshireman , the son of a woman known as Black Joan, and probably born in the East Riding . As he is said to have formed part of a pack of child-thieves which his mother ran there during "the late 1770s"  we should estimate his year of birth as circa 1772-3. We are told further that he had himself formerly been a "highly talented pickpocket" : that his principal loyalty was neither to Jonathan Strange nor Norrell but to John Uskglass, the Raven King : that he is a gifted magician able to perform spells he has learned in Norrell's service, such as Belasis's Scopus , and also to read the future by using the Cards of Marseilles : that he is able to speak French, though with a heavy Yorkshire accent , and that he has at one time been in the Yorkshire port of Whitby : and that in late February - March 1816 he has been in Norrell's service for 26 years, suggesting that he commenced around the year 1790 
Character and description
As to his person, Childermass is lean and somewhat dark in appearance. He habitually wears his black hair untied and rather long - it is twice described as "ragged". His eyes are dark, in contrast to his complexion, which is pale. Though neat and not slovenly he cares little for dress; his clothes are few and described as "ancient". He is neither profligate nor niggardly, but apparently very loath to be over-reached in a bargain, as witness his anger when he is told he must hire a blind post-horse at Grantham.
He has a businesslike air and might be said to carry himself with authority[20, 69], but though towards his fellow servants he is affable  his manner towards gentlemen, while not openly provoking, sometimes verges on the insolent[2, 30]. He appears to be reserved and a little solitary by nature.
Certainly his character is markedly independent: "Mr Childermass will do as he pleases - he always does" remarks Lucas , and the fact he feels able to leave and pursue his own line of enquiry about the missing King's Book of Magic merely by brusquely informing his master he intends to do so, speaks volumes. Mr Norrell himself remarks on this independence: "I have not the least idea what you do. It seems to me that you have been a law unto yourself from the first moment you entered my house." 
But he is also, in his way, a man of firm if somewhat secret loyalties. He may not always obey his master's orders to the letter, he may disagree with him in some or many particulars, but he gives faithful service and in the end, he does not desert Mr. Norrell: he is turned away. Above all, he is clearly devoted to the Raven King: "Nothing would please me better than that my King should come home. It is what I have wished for all my life."
He is very stoical, scarcely regarding the pain of the wound he receives from Henry Lascelles and attempting to record the marks he finds on Vinculus body by the novel method of cutting them into his own flesh. He is a man of considerable courage, as he proves by riding onto a fairy road to test whether it has again become a route into Faerie: and he is no fool, as he shews by his quick-witted avoidance the enchantment he finds there. His constitution is robust and hardy, since he chooses to ride alongside the carriage taking his master north to Hurtfew Abbey despite the severest weather. (Indeed, a complete disregard for bad weather seems a trait of his character, for when waiting in the street along with Jonathan Strange to enter the house of Messrs Minervois and Forcalquier "Childermass was entirely indifferent to the rain falling upon him.")
Relations with Mr Norrell
We learn nothing of how, in or about the year 1790, Mr Norrell came to take Childermass into his household. We see them only after they have over a course of years grown to a fair knowledge of one another's weaknesses and strengths. They are, of course, still not friends: it has been observed that true friendship can exist only between equals and while Mr Norrell is a gentleman by birth, breeding and education, Childermass is not. Neither man ever forgets this. Moreover, they are not at all alike. Childermass is a man of strong nerves and constitution answerable, and his harsh life has given him great hardihood - an indifference not to discomfort merely but very nearly to outright pain. Mr Norrell on the other hand is a valetudinarian, who cockers himself at every opportunity. One barely notices the rain falling on him, the other must be well-nigh buried in mufflers for even a carriage ride through the streets of London. Moreover Childermass is a man who, faced with a dilemma, quickly comes to a decision on how to proceed and then carries it through with fortitude, as is shewn by his response on discovering the King's Letters on the body of Vinculus. Mr Norrell on the other hand has almost no power of decision. His reluctance to commit himself to any course of action is notorious and so he habitually turns to others for help in making up his mind - to Childermass when first we meet him, and later to Strange, and, last and worst of all, to Henry Lascelles. So we may suppose that when their association first began each found in the other something missing in himself. The reclusive Mr Norrell gained a willing agent to go out into the world on his behalf - a man of activity, courage and decision who could moreover give him good advice on how best to achieve whatever ends he had in mind.*
What Childermass gains seems at first glance easy to determine. He ceases to be a vagabonding sailor or what have you, and like any valued servant he gets a position in life - a roof over his head, good food, security from want, the company of his fellows, a regular supply of money etc etc. The trouble is that nowhere do we see that John Childermass greatly cares for any of these things. He seems indifferent to comfort and lives in "a bare attic room", wears simple clothes, spends very little, is on good terms with his companions of many years, but is able to leave them without much emotion and appears "a little taken aback" to discover that they care at all for him. What has compensated him for so many years spent in the service of a man for whom he can have little natural sympathy? We must conclude, it is because Childermass was from the very first a magician, a practical magician, and desiring above all to become a better. Naturally the best place for him was at the side of the one man in England able to revive English magic, and whose house contained the greatest collection of magical lore available to the modern world.
- For example, in his dealings with the Learned Society of York Magicians. When Messrs Honeyfoot and Segundus make their application to pay their respects to Mr Norrell and admire his library, is it not odd that he at once accedes to their request? Reclusive as he is, and so jealous of his books - would we not expect him to answer with a frosty and disagreeable negative? Yet he calmly invites them into his sanctum sanctorum! And then when they pay their visit, and report it to the Society in so much excitement and yet are quite unable to be specific as to details, they arouse the suspicion they have been imposed upon. From this circumstance arises the discourteous letter Dr Foxcastle sends to Mr Norrell with the challenge to demonstrate his powers; the latter's piqued reply; his counter-challenge to the York magicians to disband themselves should he succeed - and, in short, the sure and swift destruction of as venerable a body of magical research as ever existed in the kingdom. And as a last douceur, Mr Norrell obtains what he prizes almost as much as the silencing of fellow magicians - the books formerly held in their library. Do we put this down to mere coincidence, or is there a cunning mind at work? And if so - whose?
Abilities as a magician
"Tell me, Childermass, I am curious. Does Norrell know that you go about making yourself invisible and turning yourself into shadows?
"Oh, I have picked up a little skill here and there. I have been twenty-six years in Mr Norrell's service. I would have to be a very dull fellow to have learnt nothing at all."
This interesting exchange between Strange and Childermass tells us much. As noted above, Childermass is already an adept at some forms of magic from our earliest acquaintance with him. We need not waste much time in pondering how he gained his magical education. Clearly some little of it came directly from Gilbert Norrell (who, for example, to serve his own ends, taught him Belasis's Scopus  and gave him three spells to cast when he sent him on a mission to drive Vinculus out of London ; and no doubt the rest he taught himself. As he remarks to Mr Segundus '...I have little leisure for reading - except such books as come my way in the course of my duties for Mr. Norrell.' Certainly we are given descriptions of Childermass working away at household accounts or correspondence within Mr. Norrell's library, to which he seems always to have had access; no doubt at times when Mr. Norrell was not present he might work away there on his own account. (It is amusing to think that Mr. Norrell, so sedulous in guarding his books from the eyes of all rival magicians, thereby made this precious resource available to one other at least.) It is interesting to note that when Childermass visits each of the five wives of Vinculus, for the first four, he pretends to be someone else (a milliner, a customs official, etc.), but for the fifth wife, "though he appeared to the world to be a servant of the great Mr Norrell of Hanover-square, he was in secret a magician himself." It is that fifth wife of Vinculus who is said to have fallen in love with him during his visit.
One possible sign of his confidence in his own abilities as a magician is the fact that, when Lady Pole is finally freed from her enchantment and informs Childermass and Mr Segundus that Arabella Strange and Stephen Black are still trapped in an enchantment by the gentleman with thistle-down hair, Childermass immediately states that he plans to return to Strange and Norrell and offer to help them liberate Mrs Strange and Black. 
That Childermass is by nature very sensitive to magic is made clear by his response to Lady Pole. From the time of her resurrection this unfortunate lady appears to be the nexus of particularly powerful magical forces. Firstly her appearance in the square outside his master's house causes Childermass to swoon away - a very rare condition with him, we may be sure - and secondly, when he enters Starecross Hall with the design of rescuing her, his senses are again completely disordered by her mere proximity (as are those of Mr Segundus, another man of peculiar sensibility to magic).
Childermass's skill in prognostication has been already remarked upon. Another form of magic he is able to practise is a spell of concealment, while his short answer to Mr Norrell regarding spells that no longer work - "There are thousands" - and his observation about the magical significance of roses both indicate he is more than a minor dabbler in magical arts: he is also well-read in the furthest reaches of his subject. (For example, when after the unmasking of Christopher Drawlight Mr Norrell hurriedly proposes a revival of the Cinque Dragownes, Mr Strange has no idea of what he is talking about. Childermass on the other hand not only knows about this obscure court, he even knows what number of magicians is necessary to constitute it.) He also displays his knowledge of the dangers of Fairie and fairies when he briefly enters Fairie and has a potentially dangerous encounter with the Champion of the Castle of the Plucked Eye and Heart . There is therefore every reason to suppose that his efforts at the end of the book to understand the King's Letters will not go unrewarded.
Name: The word 'Childermass' (from childer, an old north-country word for 'children' , with the addition of 'mass') usually refers to the feast which falls on 28th December, and which in the church calendar commemorates the murder of the Holy Innocents by the wicked King Herod. It has always been held a very unlucky day. As a surname it is rare, and we cannot be sure how it came to be attached to the man in question. It may of course simply be by the usual way of inheritance, but unfortunately we know nothing of Childermass' father - tho' perhaps as much as he knows himself, for what we learn of his mother gives no great cause to hope she had even that claim to respectability which marriage confers on a woman. Childermass moreover is a magician,v and prudent magicians are generally reluctant to allow the world to know their true names. And so for ought we know, Childermass may at some time in the past have decided to disguise his true name and simply plucked 'John Childermass' out of the air.
Tender feelings: Although nothing we know directly of Childermass suggests a fondness for the society of women, we are told he is able to ingratiate himself with them when he wishes - or at least, he can do so with women of a certain class. His success with the wives of Vinculus tells us this much. (It will be remembered Vinculus's youngest wife believes herself to be in love with Childermass.) His indifference to the remarkable beauty of Lady Pole however - it strikes him that she "would probably have been considered handsome by the people who cared about such things"-<nowiki> suggests no very great susceptibility. Nevertheless he particularly desires to be remembered to three of the housemaids when he leaves his master's employ; and the bantering response of the other servants implies his liking for them is not of a platonic kind[.