Lionardo remained at Florence till about the age of thirty, after which we find him at Milan, in the service of Lodovico Sforza, known by the name of Lodovico il Moro. The artist’s residence at the court of this prince, from 1482 to 1499,[2] may be considered the most active and the most glorious period of his life. Lodovico il Moro, whatever may have been his character as a potentate and as a man, certainly gave great encouragement to literature and the arts, and the universal genius of Lionardo was in all respects calculated for the restless enterprise of the time. A letter is preserved, addressed by him to Lodovico Sforza, in answer to that prince’s first invitation, (and it is sufficient to disprove Vasari’s story, that the artist recommended himself by his performance on the lute,) in which he gives a list of such of his qualifications as might be serviceable to the Duke. After an account of new inventions in mining operations and gunnery, with a description of bridges, scaling ladders, and “infinite things for offence,” in the tenth and last item, he professes competent knowledge of architecture and hydrostatics, confident that he can “give equal satisfaction in time of peace;” and adds, “I will also execute works of sculpture in marble, bronze, or clay; in painting too I will do what is possible to be done, as well as any other man, whoever he may be.” All his powers were put in requisition by the Duke of Milan. The warlike habits of the sovereigns of Italy at this time rendered the science and services of the engineer particularly useful, and Lionardo was constantly inventing arms and machinery for attack and defence. He was engaged in the architecture of the cathedral; he superintended all the pageants and masques, then so commonly conducted with splendour and taste in the Italian courts, and in some of which his knowledge of mechanics produced almost magical effects; he improved the neighbourhood of the Ticino by canals and irrigation, and attempted to render the Adda navigable between Brivio and Trezzo. The colossal equestrian statue before-mentioned occupied him, at intervals, for many years; want of means alone, it seems, prevented the Duke from commissioning him to cast it in bronze. The model existed till the invasion of Milan by Louis XII., in 1499, when it was broken to pieces by his Gascons. Footnote 2: The erroneous dates of Vasari have been corrected in this particular by Amoretti.