Chief among Lodovico's most honoured and trusted servants was Bramante of Urbino, whose genius excited so marked an influence on the development of Lombard architecture, and who was to the builders what Leonardo became to the painters of Milan. "Signor Lodovico loved Bramante greatly, and rewarded him richly," writes Fra Gaspare Bugati, a Dominican friar of S. Maria delle Grazie, the Moro's favourite church, which this great architect did so much to beautify. During this year, Bramante, having finished the palace of Vigevano and completed the new buildings at the royal villas of Abbiategrasso, Cuzzago and other places, upon which he had been long engaged, began several important works in Milan itself. The new cloister or Canonica attached to the ancient basilica of S. Ambrogio, with its graceful columns and dark-green marble capitals, and the apse of S. Maria delle Grazie, soon to be crowned with that matchless cupola that remains among Bramante's most perfect works, were both begun in 1492. A few years before, between 1485 and 1490, he had built the Baptistery of San Satiro, which another of Lodovico's chosen artists, the great Como sculptor, Caradosso, was now engaged in modelling the lovely terra-cotta frieze of children and the medallions bearing, it is said, his own portrait and that of Bramante. The noble church of S. Maria presso San Celso, which in Burckhardt's opinion combines magnificence and simplicity better than any building of the Renaissance, was the work of Bramante's assistant, Dolcebuono, and owed its erection to the munificence of Lodovico, who laid the first stone in 1491. Nor were churches and palaces the only buildings upon which Lodovico lavished his gold and employed his most distinguished masters. In those days, the hospitals of Rome, Florence, Venice and Siena were the finest in Europe, and when Luther visited Rome, he is said to have been more impressed by the size and splendour of the hospitals, than by anything else in Italy. The great Moro, determined not to allow Milan to remain behind his age in this respect, employed Bramante to adorn the Gothic buildings of the Ospedale Maggiore with the arched windows and stately porticoes that we still admire, while he encircled the cloisters with marble shafts and terra-cotta mouldings after his own heart. And in 1488, after his own recovery from illness, and that terrible visitation of the plague which had carried off fifty thousand inhabitants of Milan in six months, Lodovico founded the vast Lazzaretto, which still deserves its proud title, and may well be called a "glorious refuge for Christ's poor."
Meanwhile the works of the Duomo of Milan, that other great foundation of the Visconti dukes, were being vigorously carried on. In 1481, Lodovico had nominated his favourite Pavian master, Amadeo, the architect of the Certosa, as Capomaestro in succession to Guiniforte Solari; but the Councillors of the Fabric declined to accept his suggestion, and sent to Strasburg for a German architect, John Nexemperger of Graz, who held the office for some years, but effected little, and was finally dismissed in 1486. After his departure, the ruinous state of the central cupola requiring immediate attention, Lodovico invited Luca Fancelli, the chief architect of the Gonzagas at Mantua, to visit Milan, and by his advice Leonardo, Bramante, and other leading masters were invited in 1487 to design models for a new cupola. On this occasion Leonardo executed a model, which, however, does not seem to have satisfied the Fabbricieri, and after applying in vain to his ambassador in Rome and Florence for a master able and willing to undertake the task, Lodovico returned to his first choice, and appointed Amadeo and Dolcebuono, architects of the Duomo, with powers to alter and perfect the models of the cupola submitted to them for inspection. In order to strengthen their hands and satisfy himself, Lodovico invited Luca Fancelli of Mantua and Francesco Martini of Siena to decide on the respective merits of the models already prepared. Caradosso was sent to conduct Martini from Siena, while Gaffuri, Professor of Music, escorted Fancelli from Mantua by the duke's orders, and both masters were richly rewarded for the pains and presented with silken vests and clothes for their servants over and above the pay to which they were entitled.
On the 27th of June, 1490, a meeting was held in the Castello, at which Lodovico presided, and after much deliberation the final execution of the cupola was entrusted to Amadeo and Dolcebuono. Bramante himself was not present on this occasion, but he approved highly of the model selected, and praised its lightness and elegance.
As for Leonardo, he was absorbed in other studies, and had apparently ceased to take any interest in the subject. After allowing his first model to be spoilt, and receiving payment for a second which he never began, he had, as already mentioned, accompanied the Sienese architect, Martini, to Pavia, to give his opinion on the new Duomo in course of erection. There he lingered, studying anatomy or discussing scientific and philosophical questions with the University professors, until he was recalled to Milan, to assist in the preparations for Beatrice's wedding fêtes. Many and varied were the tasks on which Leonardo had been employed since the day, some eight years before, when the Magnificent Medici first sent him to his friend at Milan. In the letter which the young master, proudly conscious of his powers, himself addressed to Lodovico Sforza, offering him his services, he had, first of all, retailed at length his different inventions "for the construction of bridges, cannons, engines, and catapults of fair and useful shape hitherto unknown, but of admirable efficiency in time of war," after which he proceeded to give the following account of his artistic capacities:—
"In time of peace I believe I can equal any man in constructing public buildings and conducting water from one place to another. I can execute sculpture, whether in marble, bronze, or terra-cotta, and in painting I am the equal of any master, be he who he may. Again, I will undertake to execute the bronze horse to the immortal glory and eternal honour of the duke, your father, of blessed memory, and of the illustrious House of Sforza. And if any of the things I have mentioned above should seem to you impossible and impracticable, I will gladly make trial of them in your park, or any other place that may please your Excellency, to whom I commend myself in all humility."
The master had kept his word, and justified the confidence which from the first Lodovico Sforza placed in him. According to Vasari and the biographer of the Magliabecchiana, who wrote about 1540, Leonardo originally attracted the Moro's notice by the surpassing charm with which he played on a silver lyre of his own invention, and afterwards fascinated him by his conversation. But from the moment of his arrival at Milan the Florentine artist was employed by his new master to paint portraits and frescoes, to construct canals, arrange masques and pageants, or invent mechanical contrivances for use on the stage or in the house. A thousand different studies in his sketch-books and manuscripts bear witness to the strange variety of subjects upon which his versatile genius was brought to bear. But the most important work upon which Leonardo was engaged, and that which lay nearest to Lodovico Sforza's heart, was the equestrian statue of Duke Francesco Sforza. This, we learn from the master's own words, was the true reason that brought him to Milan. In a letter to the Fabbricieri of the Duomo of Piacenza, he describes himself as Leonardo the Florentine whom Signor Lodovico brought to Milan to make the bronze horse, and says that he can undertake no other task, for this will fill his whole life, if indeed it is ever finished! Countless were the designs, endless the different forms which the great master made for this model, which was, after all, never to be cast in bronze, and was destined to perish by the hands of French archers. At one time it seemed as if he could neither satisfy himself nor yet his master. In July, 1489, Pietro Alamanni, one of Lorenzo de' Medici's agents, wrote to ask his master if he could send another artist capable of executing the work to the Milanese court.
"Signor Lodovico," he says, "wishes to raise a noble memorial to his father, and has already charged Leonardo da Vinci to prepare a model for a great bronze horse, with a figure of Duke Francesco in armour. But since His Excellency is anxious to have something superlatively fine, he desires me to write and beg you to send him another master, for although he has given the work to Leonardo, he does not feel satisfied that he is equal to the task."
Probably Lodovico's confidence had been shaken by Leonardo's endless delays and hesitation, but a few months later the master was at work again, this time it appears on a completely new model of the great statue. On April, 1490, we find the following memorandum in Leonardo's writing:—
"To-day I commenced this book, and began the horse again."
But soon another interruption came to interfere with the progress of the great work. There was the visit to Pavia, and the decoration of the ball-room in the Castello, and the wedding fêtes, and the tournaments in which Messer Galeazzo sought his help. And in this year—1492—we find Leonardo at Vigevano with the Moro in March, making designs for a new staircase for the Sforzesca, and studying vine-culture, and later in the summer drawing plans of a bath-room for Duchess Beatrice, and of a pavilion with a round cupola for the duke's labyrinth in the gardens of the Castello. It was in this same year, according to Amoretti, that he finished the beautiful painting of the Holy Family, upon which he had long been engaged. This may have been the picture ordered by Lodovico as a gift for the art-loving King of Hungary, Matthias Corvinus, when his niece Bianca Maria was betrothed to that monarch's son.