The kettle hat was a brimmed helmet widely used by infantry and other soldiers because it protected the head while preserving sight and hearing.
The kettle hat is an open helmet with a broad brim — a shallow bowl over the crown with a projecting rim all round — used across Europe from the twelfth century into the sixteenth. It is the most common medieval helmet, and the one worn by the greatest number of people.
It is usually thought of as infantry equipment, and most of its wearers were infantry, but it was not a poor man's helmet by necessity. Knights and even kings wore kettle hats when vision and air mattered more than enclosure, particularly in sieges and on campaign.
Its persistence is the strongest argument for it. Few pieces of medieval military equipment remained in use, essentially unchanged in principle, for four centuries.
The simplest examples are raised from a single plate, crown and brim together, which demands real skill from the smith. Cheaper versions were made in two or more pieces, with a separate brim riveted to a skull, and some were built on the older segmented pattern.
The brim is the defining element and its angle is the design decision. A brim angled downward sheds blows and missiles outward away from the shoulders; a flatter brim gives better coverage against anything falling from directly above, which is why siege examples often have wide, level brims.
Inside it was suspended on a lining band so the shell stood off the skull, leaving a gap that absorbed impact, and secured with a chin strap. Like all helmets it was worn over a padded cap, and frequently over a mail coif as well.
Its natural environment is the siege, where the danger comes from above — stones, bolts and arrows dropped from a wall onto men working at its foot. A brimmed helmet is the obvious answer to a vertical threat, and the kettle hat appears constantly in siege imagery for that reason.
In the field it suited troops who needed to see and to shoot. Archers, crossbowmen, spearmen and billmen all wanted an unobstructed view and unobstructed breathing far more than they wanted their faces closed, and the kettle hat gives both.
It was general infantry equipment in the great battles of the later Middle Ages, worn in numbers at engagements such as the Battle of Crécy in 1346 and the Battle of Grunwald in 1410, and the grave pits from the fighting at Visby in 1361 contain examples alongside the men who wore them.
Its strengths are cheapness, comfort and awareness. A kettle hat can be made quickly, fits a range of heads, weighs little, and leaves its wearer able to see, hear, shout and breathe through a long day — which for a man in a formation is often worth more than a closed face.
Its limitation is obvious: the face is entirely open. Against a thrust to the face, or an arrow arriving flat rather than from above, it offers nothing, and no amount of brim compensates.
The brim itself has a cost. It catches on things in a press, and in a tight formation it can foul the men alongside — a small annoyance that partly explains why closed helmets were preferred once armour could be afforded.
The type appears in the twelfth century and is well established by the thirteenth, when it is shown constantly in manuscript illumination — in the Maciejowski Bible among others — worn by knights and footmen alike in field and siege.
Through the fourteenth and fifteenth centuries the form diversifies rather than replaces itself: deeper crowns, sharper brims, and versions with the brim swept down at front and back begin to shade into other helmet families.
That shading is its most interesting descendant. The fifteenth-century sallet and the later morion both carry the kettle hat's logic of a brimmed protective shell forward, and the type in one form or another outlives most of the closed helmets of the Middle Ages.
English, French, German and Italian forms differ mainly in the depth of the crown and the sweep of the brim, and the same shape appears under many names — chapel-de-fer in French sources being the most common medieval term.
The Visby finds give an unusually direct picture of what ordinary fourteenth-century head protection looked like, because the dead were buried in their equipment, and the assemblage is dominated by simple, practical helmets rather than knightly ones.
Substantial numbers survive in European collections, and their very ordinariness is why: kettle hats were made in quantity, held in municipal armouries, and reissued over generations, so more of them entered the modern record than of any grander helmet.