Reports now got about touching his heresies and atheism, and it became increasingly difficult for him to remain in Florence. Ser Piero introduced him to Lorenzo de' Medici; uselessly, however, for Il Magnifico disapproved spirits too daring and unconventional, and demanded a constant and servile adulation which Leonardo was ill fitted to supply. The tedium of inaction oppressed him. He entered into negotiations with the Egyptian ambassador for the purpose of obtaining the post of chief architect to the 'diodario' of Syria, though he knew that it would require his embracing the Mahometan faith. His one desire was to escape from Florence. Chance favoured him. He made a many-stringed silver lute in the form of a horse's head, which took Lorenzo de' Medici's fancy. Lorenzo sent it by the hand of the inventor to Milan, as a gift to Ludovico Sforza.
Leonardo was received at the Lombard court not as a man of science, not as a painter, but as the sonatore di lira—the 'player of the lyre.'
But before starting he had written a long letter to the duke, setting forth how useful he might be to him.
'Most Illustrious Lord,—Having studied and estimated the works of the present inventors of warlike engines, I have found that in them there is nothing novel to distinguish them. I therefore force myself to address your Excellency that I may disclose to him the secrets of my art.
'1st. I have a method for bridges, very light and very strong; easy of transport and incombustible.
'2nd. New means of destroying any fortress or castle (which hath not foundations hewn of solid rock) without the employment of bombards.
'3rd. Of making mines and passages, immediately and noiselessly, under ditches and streams.
'4th. I have designed irresistible protected chariots for the carrying of artillery against the enemy.
'5th. I can construct bombards, cannon, mortars, 'passavolanti': all new and very beautiful.
'6th. Likewise battering rams, machines for the casting of projectiles, and other astounding engines.