In the centuries following the fall of the Western Roman Empire, medieval Europe lost extensive knowledge and expertise across various fields, from architecture to agricultural techniques. This regression is particularly evident in siege warfare. Early medieval sources are notably scarce in references to siege engines, and they are mentioned only occasionally, as in the case of the Norse siege of Paris in 886. However, from the 11th and 12th centuries onward, mentions of siege engines become increasingly frequent, especially with the First Crusade. References soared during the conflicts between the Italian city-states and Frederick Barbarossa. By the 13th century, the names of military engineers began to appear regularly; they became so important that one of them, the Spaniard Calamandrino, captured by the Brescians after a sortie in 1238, managed, due to his skill in constructing siege engines, to halt the siege of Brescia, thus preventing the complete fall of the Guelph front.

However, the profession of siege engineer could also be fraught with hazards, as evidenced by an incident in 1232 involving a Veronese engineer defending the castle of Nogarole, which was under siege by the Mantovans. In this case, he built a siege engine called the librilla, but somehow became entangled in it and was flung into the air, landing—fortunately unscathed—in the Mantovan camp. He was luckier than the unfortunate donkeys catapulted by the Florentines over the walls of Arezzo in 1289, dressed in liturgical garments as a mockery directed at the bishop of Arezzo. The Florentines showed a traditional enmity toward this animal, having launched five donkeys into Siena a few decades earlier, in 1233. The Bolognese, however, showed an even more ruthless approach; in 1249, they launched a live donkey over the walls of Modena.

These practices were not without purpose: they served to boost the morale of the besieging troops and to psychologically attack the enemy, producing, in any case, a degree of amusement for later historians.