name

Even Jehanne's name has been the subject of chronic (and largely pointless) controversy.
While it's not known beyond a doubt who actually wrote the signatures which appear on several surviving documents (two of which are shown above), the verdict among historians is that she must have written them herself. The handwriting is consistent in each signature even though the body text varies widely from one document to the next, and, even more significantly, the signatures are similar but not identical, which would refute the theory that someone guided her hand to write a single prototype from which an impression was made.
The lettering improves markedly with each successive note (especially evident in the large 'J' at the beginning of her name, which becomes increasingly rounded and graceful); this may be an additional indication that the signatures were indeed written by an illiterate farmer's daughter just learning to write her own name. If so, it's likely that her confessor, Jean Pasquerel, was the one who taught her this skill, as he seems to have been her chief scribe in the army: his own name appears on one of her letters, and he is believed to have also recorded at least one, and probably more, of the additional letters she dictated. For whatever it may be worth, handwriting experts have analyzed these signatures and concluded that they were written by a left-handed woman who was steadily gaining in general confidence during the period when the signatures were written. Left-handers the world over have enthusiastically embraced the idea that Saint Joan may have been one of their own number.
Margin Note 1: Right-handers like myself are more skeptical, of course... Another point of contention: there are those who strenuously object to the modernized version of her family's surname (d'Arc, meaning "of Arc", instead of the medieval "Darc"). The lack of any apostrophe in 15th century contractions has left the matter open to speculation, although the Latin form, "Darco", has been taken to indicate that it was simply a name rather than a contracted phrase. (Those who are interested in the gritty details for the various pro and con arguments invoked in this momentous intellectual battle).
Inevitably, those scholars who favor the "contraction hypothesis" are further divided into two camps: those who believe that the name "of Arc" merely indicates place of origin, versus those who believe that it indicates feudal ownership and therefore noble lineage (i.e., aristocratic roots prior to the family's ennoblement by Charles VII in 1429). The issue is largely moot, since there wasn't any meaningful distinction between the lowest noble families and the more prosperous farmers: the aristocracy was constructed along the same 'pyramid' form as the rest of society, meaning that there were thousands of petty nobles at the bottom of the scale who lay within the economic gray area where the Second and Third Estates overlapped. By necessity such families often intermarried with commoners, blurring the line between the two classes. The moderate prosperity of the Darc family could indicate that they were either a faded remnant of an old noble house, or a rising peasant family; either way, it would make little practical difference.
In the medieval manuscripts, the name appears in numerous forms: Darc, Tarc, Tart, Dare, Day, Daix, etc. The latter two spellings (Day and Daix) were attempts to reflect the pronunciation used by the family itself: in their native dialect the final consonants were dropped and the vowel shortened. The spellings which use a 't' for the initial consonant are believed to reflect the sharp pronunciation of 'd' in the same dialect.
On top of this hefty collection of alternate spellings, we also have an entirely new surname, "du Lys" ("of the Lily") which was granted to the family by Charles VII when he issued them a patent of nobility on December 29, 1429, in the middle of Jehanne's military campaigns (see the associated coat of arms at the bottom of this page). The form "Darc du Lys" occurs in the documents as a surname for her brothers.
She herself doesn't seem to have used a surname, as she generally referred to herself as "la Pucelle" (meaning "the maiden" or "virgin"), having sworn to maintain her virginity "for as long as it should please God" around the age of 13. When asked at her trial to give her surname (on February 21, 1431), she said she knew nothing of it, and later, on March 24, said that her surname was either Darc or Romée (the latter being a title or nickname given to her mother for having completed a pilgrimmage to Rome), explaining that in her region girls were known by their mother's surname(one of many medieval variations). These responses have puzzled some authors; I think the simplest explanation is that she was always called by her first name in her small village, and may have been confused at first by the term "surname" in an era in which surnames were not used in any consistent fashion.
Margin Note 2: Some pop authors have tried to claim that this was a surviving relic of some sort of pagan culture, which is nonsense: it's simply one of countless variations found in that era.
Her first name, "Jehanne" or "Jhenne" ("Joan" or "Joanna" in English) was virtually the most common female name in that era, appearing prominently and repeatedly in all French families of the late medieval period. And yet, outrageous conclusions have been drawn based on this name: for instance, some authors have solemnly informed us that the name was "common among witches", as if to imply that the witchcraft charges against her were true based solely on her name (despite the fact that her conviction was on allegations of heresy rather than witchcraft: her accusers themselves dropped all of the witchcraft charges before drawing up the final 12 articles of accusation). Using similar logic, we would have to conclude that St. Joan was a Duchess, since there were so many Duchesses named Jehanne, (and Countesses, Baronesses, nuns, prostitutes...). Her name was so common, in fact, that some scholars have speculated that she was called "La Pucelle" partly in order to distinguish her from the vast multitude of other Jehannes in 15th century France. In her native village she had been nicknamed "Jhennette" ("little Joan"), a common affectionate form of the name which may have also distinguished her from the older Jehannes in her village, of whom at least three are known to us: Jehanne de Viteau, Jehanne Royer, and "Aubéry's wife" Jehanne, all of whom had served as her godmothers. Margin Note 3: Or, to use a modern example: someone could point out that there are a great many dentists named "Bob", therefore (following the same logic) Bob Dylan, Bob Costas, and Bob Dole must naturally all be dentists...
Below is a drawing of the family's coat of arms ("Azure, between two fleurs-de-lis Or, a royal crown of the second, supported by a sword Argent fleurdelisé and pommelled of the second") as it appears in the letter (dated June 2, 1429) in which Charles VII formally granted the arms.