At the centre of this sheet Leonardo drew an exploding projectile, with fins for accuracy, to be fired from a ballista (akin to a huge crossbow). On impact the rear of the missile would be driven into the front part, here shown in cutaway, to detonate its load of powder. At lower right is the head of a halberd with a spike flanked by two toothed blades, one of many such pole weapons drawn by Leonardo during the mid-1480s, with more concern for their decorative qualities than their effectiveness.

Leonardo’s career coincided with the introduction of gunpowder into European warfare, and his many military drawings of the 1480s (see RCIN 912647, 912649-912653) include designs for both the old type of weapon – lances, chariots, enormous catapults and crossbows – and the new – guns, cannon and mortars. It is unlikely that any of these designs was put into practice, and indeed Leonardo could be dismissive of such inventions, noting that ‘they often do no less damage to one’s friends than to one’s enemies’.

A number of his ideas were derived from woodcuts in a printed edition of Roberto Valturio’s De re militari, a treatise on warfare written around 1450 and published from 1472 onwards, an edition of which was owned by Leonardo. He may have been considering producing a treatise of his own, with designs improving upon those illustrated in Valturio.

Text adapted from Leonardo da Vinci: A life in drawing, London, 2018