The Commission
The completed central section ("Fight for the Standard") was approximately 15 × 20 feet, on the east wall of the Salone dei Cinquecento, Palazzo Vecchio, Florence. The full mural was intended for a wall approximately 54 × 21 feet. Commissioned by Gonfaloniere Pier Soderini (contract signed by Niccolò Machiavelli).
Leonardo vs. Michelangelo
Leonardo was assigned the east wall while Michelangelo took the opposite wall for the Battle of Cascina — the only time these titans worked on the same project. Neither finished. The depicted battle (June 29, 1440) saw Florence defeat Milanese forces. The central composition shows four horsemen violently grappling for a battle standard — conveying extraordinary fury, twisted expressions, and gnashing horse teeth.
Peter Paul Rubens' celebrated copy (now in the Louvre) is the finest surviving record of what Leonardo achieved.
The Catastrophic Technique
Leonardo used an experimental encaustic/oil hybrid technique drawn from Pliny the Elder's Historia Naturalis: oil colors applied over a thick undercoat mixed with heated beeswax on a wall sealed with gypsum and rosin. He set up charcoal braziers to dry the wax-oil paint.
The technique failed catastrophically:
- The vast wall couldn't be heated evenly
- The wax melted rather than dried
- Paint dripped down the wall
- A fierce storm on June 6, 1505 damaged the cartoon during transfer
Cerca Trova — "Seek and You Shall Find"
When Giorgio Vasari renovated the hall (1555–1572), Leonardo's remnants vanished beneath new frescoes. Vasari painted a tiny green flag bearing the words "CERCA TROVA" 12 meters above ground in his Battle of Marciano. Was this a message to future seekers?
Maurizio Seracini's decades-long investigation discovered a curtain wall with a 1–3 cm gap behind Vasari's fresco. In 2011–2012, endoscopic probes retrieved black pigment samples matching those used by Leonardo in the Mona Lisa and Saint John the Baptist.
However, over 100 art historians signed a petition opposing the investigation, and a 2019 anthology argued Leonardo never actually painted the mural. Seracini was ordered to stop investigations. The question remains unresolved.