Part 99 - Metallurgy & Maille, Pt 3

by Lord Thomas the Black


Metallurgy and Maille, pt 3

            Welcome back to another edition of Blackmaille!

            Last  time around, we examined how advances in the science of metallurgy in turn led to advances in armor, especially maille. This month, we (finally) wrap up our three-part series with an in-depth look at how these same advances led to the rise and subsequent fall of the Italian armor industry.

The Transitional Period

            The use of plates to improve the performance of maille had started to come into general use during the 13th century. The knees and shins (those areas on cavalrymen most vulnerable to attack by infantry) were protected by reinforcing plates of metal (or perhaps cuir-bouilli) from around 1250 CE, and arm defenses were added later in the century1.

            A mid-13th C effigy of St Maurice from Magdeburg Cathedral shows what maay have been a coat-of-plates, worn on top of the customary maille hauberk. The practice of wearing a heraldic surcoat over the armor makes it somewhat difficult to tell from the effigy exactly what sort of armor a knight might have been wearing. The appearance of rivet heads on top of the cloth may suggest a coat-of-plates, but may also just be decorative. A one-piece breastplate in the Bavarian National Museum has two such rows of rivets, giving it the appearance of a multi-plate defense, when in fact it is nothing of the sort2

            There are written references to trade in armor plates before 1300 in the chronicle of Bonvesin de Riva3. A merchant called Frederick the Lombard collected together in Bruges in 1295 for the fleet of King Phillip of France the impressive total of:

                        2853 helmets

                        6300 round shields

                        4511 maille shirts

                        751 pairs of gauntlets

                        1374 gorgets

                        5067 coats of plates

So clearly there was already a substantial demand for “plates” to reinforce maille armor by the late 13th C. Such plates would have been perhaps 15cm X 10cm in size, at most. Instead of iron, they might have been made of cuir-bouilli (literally “boiled” but perhaps better “hardened” leather), then attached to a fabric jerkin and worn over the maille shirt. Cuir-bouilli seems to have enjoyed a brief period of popularity around the early 14th C. Although lightweight, it didn't protect very well, so it soon fell out of fashion, and few examples have survived4.

            Fragments from 24 coats-of-plates (hereafter COP) were excavated from the mass grave at Wisby after the battle of 1361, as well as large quantities of maille. These belonged to the defenders of the city of Wisby and, oddly, they were discarded rather than salvaged and re-used. Modified forms of the COP, with more (but smaller) plates, known as a 'brigandine” or “jack of plates” remained popular forms of defense until the late 16th C. The brigandine was made up of small, overlapping plates riveted to a canvas doublet. The jack, originally a simple quilted doublet, consisted of plates sewn between two layers of fabric. Both were means of recycling old armor into a cheaper defense for the infantry5.

            During the course of the 14th century, the plates of the COP became larger in size but fewer in number, until they could be regarded as a rudimentary breastplate with some smaller plates attached.    Such coats of large plates were still worn over a maille shirt at the end of the 14th C. The logical next step was the complete replacement of maille (as far as possible) with plate, which offered better protection for roughly the same weight (maybe less than the combination of COP and maille). This change began in the 14th C and was completed by the early part of the 15th C6.

            Once plates of sufficient size (2.5 – 4.5 kg) could be made, then the whole body could be covered with a complete armor of plates, except for the joints of the limbs, the armpits, and groin, which were still protected by gussets of maille. Once the difficulty of making such suits has been overcome then all sorts of other advantages may be seen (such as glancing surfaces to deflect arrows).

            However, seeing the advantages of plate armor does not automatically make their manufacture easy. A plate of armor between 2.5 and 4.5 kg will pose new challenges to the makers. Billets of metal of 10kg or more may be needed to make such a plate, and their production from a bloomery is difficult. The metal must be reasonably low in slag if its structural properties are to be suitable for armor. During the 14th C in Italy, these large plates did appear, and they are generally plates of steel. As a result, European armor starts to differ fundamentally in design from the lorica segmentata used by the Romans, and those forms of armor used in other parts of the world, like the Middle and Far East. All of those cultures continued to use armor made up of a large number of small plates or rings joined together to form a flexible garment, rather than a rigid exoskeleton7. The best Italian armor made for knightly customers in the 14th and 15th centuries was generally made of steel, and frequently hardened by heat-treatment. Being made of steel, they would offer a much better defense against nearly all weapons8.


            All throughout the Middle Ages, Lombardy was one of the major centers of economic activity in general, and metal production in particular, in Europe. This was especially concentrated in the free cities of Milan and Brecia, whose economic life flourished after the end of the Hohenstaufen dominion (around 1260 CE). Constantly increasing demand overseas gave Lombard armorers considerable markets.  The needs of the crusaders and Latin states of the East offered an alternative to the Papal Interdict (1170) forbidding trade with the Muslim world. Lombard armorers would meet the demands of their customers in the Levant, whether Genoese or Venetian. In addition, the paid princely armies (which largely replaced feudal hosts) provided yet more customers. Starting in the 14th C, there appears in the archives of the Milanese and Brescian armorers massive orders for hundreds or even thousands of pieces of equipment9.

            The Chronicle of Milan by Bonvesin de Riva (1288) records: There are in this place an amazing number of weapon forges, that produce daily every kind of arms, like maille shirts, coats of plates, breastplates and splints, great helmets, bascinets, caps, collars, gloves, greaves, cuisses and polyns, spears, and swords, etc. They are all from hardened and polished steel, gleaming like mirrors... There are shield-makers, who manufacture shields and other weapons in incredible numbers. From here this city supplies other cities of Italy with all kinds of weapons, by whom they may be exported even to the Tartars and Saracens”10.

            The Missaglia were the greatest arrmor-makers of the 15th C, and according to some enthusiastic collectors, ever. Without guild restrictions on the number of craftsmen employed, Milanese entrepreneurs like the Missaglia could employ large numbers of sub-contractors (each specializing in making only one part of a harness)11.  If the master craftsman took charge of all aspects of a complex production, their workmen, in turn, had to specialize. This is particularly clear for the makers of armor, for whom many contracts for hiring workmen have survived. These almost always specify that the workmen will be making cuirasses or helmets or arms and legs12. The division of work and the supervision of the master can be shown in the armorers' marks; each piece was signed once by the workman who made it and also by the master who directed the final assembly of the whole armor13.

            Throughout the 15th C Milanese armor making was dominated by the Missaglia family, who served the Visconti and Sforza dukes of Milan, the Gonzaga of Mantua, the Este of Ferrara, and the Medici of Florence. They ran shops in Rome, Naples, Barcelona, and Tours. The commercial success of the Missaglia raised their social status, especially of the Sforza, who were often in debt to them. In 1458 the duke interceded on behalf of Antonio Missaglia (head of the business from 1452 to 1496) to save his brother Cristoforo from the gallows. In 1469 the duke gave Antonio an armorer's mill outside the city walls for an annual rent of one helmet14. By the end of the century, the Missaglia possessed half a dozen workshops, exploited two mining areas well endowed with smelting installations, and had branch establishments in the kingdom of Naples and in Spain. Their business was reckoned in hundreds of thousands of scudi, and their properties were classed among the most wealthy in Milan15.

The Metallurgy of Italian Armor

            Much armor is described as “Italian” or “Milanese” as if these terms were interchangeable, and to some extent, this is true. Milan was the center of Italian armor production, and a cornerstone of the Lombard economy and iron trade. Most (but not all) makers' marks which can be identified belong to Milanese or Brescian craftsmen. For the purposes of this essay, I will be discussing Northern Italian armor, without discussing its city of origin.

            The starting point for identification has to be the makers' marks stamped onto the pieces of armor. Many of these can now be identified, and the attributions of Boccia (1967, 1982) have generally been followed. Some Italian craftsmen were, in later years, induced to work at the courts of Burgundy, Spain, and England.

            According to Boccia, makers' marks fall into three types:         

1.)                A group of three, arranged like this:                  


                                                      B        B

“A” is the monogram of the armorer, I.E. the shop owner who undertook the contract for the work, and who guaranteed the product. “B” is the monogram of the specialist craftsman who was responsible for its quality to the armorer.

2.)                A group of two:        

                                                C        C

“C” is the monogram of the craftsman, and Boccia believed that this indicated that the piece had been put to the “test of the big crossbow”

3.)                A single mark:


“D” is also the monogram of the craftsman but, according to Boccia, indicated that it had only been tested by a bow or “little” crossbow.

            The suggestion that the number of marks is an indication of the degree of protection offered is due to Buttin. According to the statutes of the Armourers of Paris (1451) armor that had been (allegedly) proved by a missile from a steel crossbow was described as “a toute epreuve” while that tested only by a lever-crossbow was “a demi-epreuve”16.

            The metallography of a large number of specimens of Italian armor shows that general conclusions can be drawn about the material that was used and the extent to which armorers heat-treated their products to harden them. Armor (with or without marks) is almost always made of steel in 15th C Italy, and in just over half of the marked examples studied17, it is a medium-carbon steel. In two-thirds of the marked examples, some attempt has been made to harden them by heat-treatment, which has been successful in around 1/3 of all cases.  Armor bearing an armorer's mark is of a decidedly better quality than armor without such a mark. 45 out of 72 marked armors were hardened, compared to only 12 out of 45 unmarked18. Armor without marks, but of Italian provenance, is made of steel, but usually of lower carbon content. Indeed, that proportion which was made of medium-carbon steel is somewhat less than half. It is, however, seldom hardened by any form of heat-treatment (and those which were hardened may have had marks which are now obscured). A group of infantry armors, some which carry marks, is included in this category19.

            It is clear, then, that the mark was a sign of higher-quality armor, which the customer would have expected to have been made of harder steel. The different metal used for that category of armor without marks (but of Italian form) might be thought to cats doubt upon its Italian origin. But not all Italian armor was necessarily made of the best metal available. If the form, and provenance, suggest an Italian origin, it is quite plausible that armor made of poorer metal had been identified as such by its maker, and sold unmarked at a lower price20. Think of it like an outlet shop. The lesser-quality stuff may not have the designer label on it, but it came from the same factory nonetheless.

The Decline of an Industry

            There are three major changes in the nature of Italian armor which take place within a few years of one another around the turn of the 16th century.

            The first change, and most importantly, is that the armor is almost never made of hardened steel after around 1510. This is an abrupt change, and not easy to explain convincingly. This change coincides with the adoption of fire-gilding. This process seems to have been used for the decoration of armor from about 1490 onwards. The breastplate ascribed to Bartolomeo Colleoni (Vienna, A.183) is one of the earliest examples of such decoration. It rapidly became very common, and increases in extent until half or more of the surface is covered by fire-gilded decoration. Examples of gold decoration on armor are known before 1490, but it may not have been fire-gilding. Gold paint, for example, would require no heating, although it would have been far less permanent. “Fire-gilding” by applying a solution of mercury, and then heating to boil away the mercury was capable of fixing a permanent thin layer of gold upon other, cheaper metals, but the heating would rapidly reduce the hardness of quenched steel. Evidently the one operation (gilding) was found to interfere with the other (hardening). The two operations were very seldom carried out in later Italian armor21.

            Other centers of armor production adopted fire-gilding during the late 15th C, but with the same consequences. South German armor was being made of hardened steel by the end of the 15th C, almost as their Italian rivals were abandoning this technology, and they continued to harden it for another 100 years. Very few Italian armors are both gilded and hardened. This might be explained by the Italians' less certain mastery of the techniques for hardening steel; a preference for slack-quenching being less conspicuous in the 15th C, while their South German rivals preferred quenching and tempering, which is easier to combine with fire-gilding. Throughout the 16th C, armor made for the more affluent customer was now made with patterns of etching and gilding. The techniques of heat-treatment employed to harden the steel were evidently found to be incompatible with the heating needed for fire-gilding. Their South German rivals seem to have been more successful at combining the two operations because they followed a different order of procedure, gilding their steels after quenching, but before tempering. What is surprising, however, is that plain armors, presumably for field use, are not hardened either. In fact, they are made of very poor metal. Why there should be such a shift in their priorities is less easy to understand22.

            The second change is that the use of armorers' marks becomes relatively uncommon, and effectively disappears after 1510, although some gilded armors are signed (rather than marked) later in the century. If the use of a mark was intended to be a sign of the quality of the metal employed to make the armor, then when most customers were no longer interested in that quality, its disappearance would logically follow23.

            The third change is a less frequent use of steel in the early years of the 16th C, although perhaps economic factors might be partially responsible for this. The French invasion of 1494 introduced modern mobile artillery too Italy, and the subsequent 30 years of intermittent war dislocated the economic life of Italy in general and Milan in particular. In general, there was a revival in the use of steels in 1530, which lasted until the end of the century. Even the cheapest armor was generally made of a low-carbon steel, which is more than can be said for the cheapest German armor24.

            There was, of course, an alternative method of improving the defensive qualities of the armor which was less demanding on the armorer, and that was to make it thicker. Increasing the thickness of a 2mm plate to 3mm more than doubled its effectiveness. So the problems of heat-treatment could be avoided, providing that their customers were prepared to wear heavier armor25.

            The final flourish of the Milanese armor industry was the production of some extraordinary armors by the Negroli family, and their  competitors, in the second quarter of the 16th century. They produced armors which allowed noblemen to pose as Hercules, Alexander, or a Roman Emperor, and to dress up as sea-serpents, lions, or dragons. Armor was forged into shapes which almost defy description, and appear to have been wholly impractical, yet its metallurgy remained that of a functional defense. Filippo Negroli was regarded as the finest armorer of his day, and made Milan, at least for a little while, the center of the industry once again26

            At first sight, it may seem surprising that a material more than twice as hard as iron should be used for “parade” armors, but there are several possible reasons for this. One factor which should be considered is that the hardness of the metal enabled the armorer to demonstrate his virtuosity, just as sculptors in the hardest stones demonstrated the highest levels of mastery. An additional, and more practical, consideration is that steel would contain far fewer brittle slag inclusions than iron, so that certain techniques employed after forging (such as chasing) might be easier27.

            But the most important reason for using steel is surely the motive for making these armors in the first place. If they had been intended to be used purely for decoration, then it would have been logical to use the softest metal available (copper, or even silver) as that would have been easiest to work. The Negrolis were regarded as the best armorers of Italy, and they used the best steel available for their “parade” armor, as did their leading rivals. Decorative though these “parade” armors were, they were still armor. In design, they were intended to show their wearers as classical heroes, and their ornate form might lead the modern observer to think that because they were primarily for parade, they must be fit ONLY for parade. In fact, they were metallurgically every bit a functional as  any contemporary field armor. Surprising as it may be, it is found that parade armors in general were made of better metal than the plain field armors of the 16th century28.

            It is particularly surprising because even if Italian armorers seem to have been only able to offer a choice between hardened or decorated armors, while many 16th C German armorers could offer both together, one might still have expected plain Italian armors for battle to have been hardened – but they seldom were, and not after 1530. The difficult processes of hardening and tempering were evidently though to be unprofitable, especially as there was a simpler method of improving the defensive qualities of armor (making it thicker).

            It seems clear that while princes and nobles ordered expensive armors to wear on parade, these armors were expected to be fit for war, even if in practice they might seldom be worn in combat. For the sordid business of  sieges and campaigns, where there was no opportunity to impress, the cheapest armor would suffice. Either way, Milan and Brescia continued to make mass-produced armor of modest price until well into the 17th century29.

            So there you have it. Quite a lot to take in, I know. If you wish to know more on the subject, I highly recommend Williams' “The Knight and the Blast Furnace”, from which much of my research was drawn. This impressive tome is available through your local library via inter-library loan, or can be found on and other online retailers for around $300.00. Price's “Techniques of Medieval Armor Reproduction” is another valuable resource, and one no armorer's workshop should be without.

            Thanks for joining us for another month! As usual, any questions, comments, fan mail or hate mail can (and should) be sent to me at:

                                    Thomas Beckett
                                    13628 Belmead Ave
                                    Grandview, Mo 64030

Or you can email me at

            See you next month!


1Price, Brian  “Techniques of Medieval Armor Reproduction”  Paladin Press, 2000

2Williams, Alan “The Knight and the Blast Furnace”  Brill-Leiden, Boston, 2003, pg 54

3Quoted in Pfaffenbichler, M “Armorers” (London, 1992), pg 33

4Williams, pg 54

5Ibid, pg 55


7Ibid, pg 56


9Francesco Datini, an armor merchant from Prato, established himself at Avignon, where an inventory of 1367 lists 45 bascinets, 3 iron hats, 10 cervellers, 60 breastplates, 20 cuirasses, and 12 maille hauberks. These archives are a reflection of the armor commerce between1363 and 1416, showing a constant flow of armor along the routes from Milan and Brescia to Avignon, Pisa, and Naples.

10Quoted by Menant, 133. Madodio – in Thomas and Gamber (1958), pg 714

11Williams, pg 57

12Ibid, pg 58




16Buttin,C. “Notes sur les arures a l'epreuve” Revue Savoisienne, 2/3 (Annecy, 1901) pg 64-85. Quoted in Williams, pg 61

17Williams, “The Knight and the Blast Furnace”

18Williams, pg 66


20Ibid, pg 67

21Ibid, pg 203


23Ibid, pg 204



26Ibid, pg 201


28Ibid, pg 211



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