The roundel dagger is an auxiliary weapon used by European men-at-arms from the second half of the 14th century. It is characterized by the two metal roundels (washers) which form its guard and its pommel. These wheels are intended to form an unassailable mass when the fist armed with a soldier's gauntlet closes on the hilt. Thus, the handle is short and the wheels "frame" the gauntlet perfectly. The 30 to 50cm blade is very thick to be rigid but narrow in order to pass through the faults of the opponent's armor, to the point of sometimes having a triangular section such as percemaille.
In the Middle Ages, these weapons caused wounds that were often fatal, since they were deep and therefore impossible to treat with the medicine of the time. While the slashes remained the most effective with the sword, it is the thrust which is the most effective with the knife (one dies immediately from a slash if it was well carried, whereas one survives a thrust for a few minutes, even if it has been given perfectly, unless there is an attack on the heart or the brain. Nevertheless, the knife does not allow you to cut a man in two with a single blow. , the thrust is therefore the best choice, undeniably), hence the appearance and the very rapid popularization with the whole troop of the dagger. The terrible effectiveness of this weapon is immediately recognized by the whole world and this weapon is synonymous with catfighting, assassination, absence of mercy, even making the famous German master of arms Hans Talhoffer say:"They come from there to the dagger, God help them! .
We find relatively similar 'crafts' in certain 'trench knives' made for hand-to-hand combat by the combatants of the First World War