Colleoni was by no means deficient in those foxlike qualities which were necessary to save the lion from the toils spread for him by Italian intriguers. He had already shown that he knew how to push his own interests, by changing sides and taking service with the highest bidder, as occasion prompted. Nor, though his character for probity and loyalty stood exceptionally high among the men of his profession, was he the slave to any questionable claims of honour or of duty. In that age of confused politics and extinguished patriotism, there was not indeed much scope for scrupulous honesty. But Filippo Maria Visconti proved more than a match for him in craft. While Colleoni was engaged in pacifying the revolted population of Bologna, the Duke yielded to the suggestion of his parasites at Milan, who whispered that the general was becoming dangerously powerful. He recalled him, and threw him without trial into the dungeons of the Forni at Monza. Here Colleoni remained a prisoner more than a year, until the Duke's death in 1447, when he made his escape, and profited by the disturbance of the Duchy to reacquire his lordships in the Bergamasque territory. The true motive for his imprisonment remains still buried in obscure conjecture. Probably it was not even known to the Visconti, who acted on this, as on so many other occasions, by a mere spasm of suspicious jealousy, for which he could have given no account.
From the year 1447 to the year 1455, it is difficult to follow Colleoni's movements, or to trace his policy. First, we find him employed by the Milanese Republic, during its brief space of independence; then he is engaged by the Venetians, with a commission for 1500 horse; next, he is in the service of Francesco Sforza; once more in that of the Venetians, and yet again in that of the Duke of Milan. His biographer relates with pride that, during this period, he was three times successful against French troops in Piedmont and Lombardy. It appears that he made short engagements, and changed his paymasters according to convenience. But all this time he rose in personal importance, acquired fresh lordships in the Bergamasque, and accumulated wealth. He reached the highest point of his prosperity in 1455, when the Republic of S. Mark elected him General-in-Chief of their armies, with the fullest powers, and with a stipend of 100,000 florins. For nearly twenty-one years, until the day of his death, in 1475, Colleoni held this honourable and lucrative office. In his will he charged the Signory of Venice that they should never again commit into the hands of a single captain such unlimited control over their military resources. It was indeed no slight tribute to Colleoni's reputation for integrity, that the jealous Republic, which had signified its sense of Carmagnola's untrustworthiness by capital punishment, should have left him so long in the undisturbed disposal of their army. The Standard and the Bâton of S. Mark were conveyed to Colleoni by two ambassadors, and presented to him at Brescia on June 24, 1455. Three years later he made a triumphal entry into Venice, and received the same ensigns of military authority from the hands of the new Doge, Pasquale Malipiero. On this occasion his staff consisted of some two hundred officers, splendidly armed, and followed by a train of serving-men. Noblemen from Bergamo, Brescia, and other cities of the Venetian territory, swelled the cortege. When they embarked on the lagoons, they found the water covered with boats and gondolas, bearing the population of Venice in gala attire, to greet the illustrious guest with instruments of music. Three great galleys of the Republic, called Bucentaurs, issued from the crowd of smaller craft. On the first was the Doge in his state robes, attended by the government in office, or the Signoria of S. Mark. On the second were members of the Senate and minor magistrates. The third carried the ambassadors of foreign powers. Colleoni was received into the first state-galley, and placed by the side of the Doge. The oarsmen soon cleared the space between the land and Venice, passed the small canals, and swept majestically up the Canalozzo among the plaudits of the crowds assembled on both sides to cheer their General. Thus they reached the piazzetta, where Colleoni alighted between the two great pillars, and, conducted by the Doge in person, walked to the Church of S. Mark. Here, after Mass had been said, and a sermon had been preached, kneeling before the high altar he received the truncheon from the Doge's hands. The words of his commission ran as follows:—
'By authority and decree of this most excellent City of Venice, of us the Prince, and of the Senate, you are to be Commander and Captain General of all our forces and armaments on terra firma. Take from our hands this truncheon, with good augury and fortune, as sign and warrant of your power. Be it your care and effort, with dignity and splendour to maintain and to defend the Majesty, the Loyalty, and the Principles of this Empire. Neither provoking, not yet provoked, unless at our command, shall you break into open warfare with our enemies. Free jurisdiction and lordship over each one of our soldiers, except in cases of treason, we hereby commit to you.'
After the ceremony of his reception, Colleoni was conducted with no less pomp to his lodgings, and the next ten days were spent in festivities of all sorts.
The commandership-in-chief of the Venetian forces was perhaps the highest military post in Italy. It placed Colleoni on the pinnacle of his profession, and made his camp the favourite school of young soldiers. Among his pupils or lieutenants we read of Ercole d'Este, the future Duke of Ferrara; Alessandro Sforza, lord of Pesaro; Boniface, Marquis of Montferrat; Cicco and Pino Ordelaffi, princes of Forli; Astorre Manfredi, the lord of Faenza; three Counts of Mirandola; two princes of Carpi; Deifobo, the Count of Anguillara; Giovanni Antonio Caldora, lord of Jesi in the March; and many others of less name. Honours came thick upon him. When one of the many ineffectual leagues against the infidel was formed in 1468, during the pontificate of Paul II., he was named Captain-General for the Crusade. Pius II. designed him for the leader of the expedition he had planned against the impious and savage despot, Sigismondo Malatesta. King René of Anjou, by special patent, authorised him to bear his name and arms, and made him a member of his family. The Duke of Burgundy, by a similar heraldic fiction, conferred upon him his name and armorial bearings. This will explain why Colleoni is often styled 'di Andegavia e Borgogna.' In the case of René, the honour was but a barren show. But the patent of Charles the Bold had more significance. In 1473 he entertained the project of employing the great Italian General against his Swiss foes; nor does it seem reasonable to reject a statement made by Colleoni's biographer, to the effect that a secret compact had been drawn up between him and the Duke of Burgundy, for the conquest and partition of the Duchy of Milan. The Venetians, in whose service Colleoni still remained, when they became aware of this project, met it with peaceful but irresistible opposition.
Colleoni had been engaged continually since his earliest boyhood in the trade of war. It was not therefore possible that he should have gained a great degree of literary culture. Yet the fashion of the times made it necessary that a man in his position should seek the society of scholars. Accordingly his court and camp were crowded with students, in whose wordy disputations he is said to have delighted. It will be remembered that his contemporaries, Alfonso the Magnanimous, Francesco Sforza, Federigo of Urbino, and Sigismondo Pandolfo Malatesta, piqued themselves at least as much upon their patronage of letters, as upon their prowess in the field.
Colleoni's court, like that of Urbino, was a model of good manners. As became a soldier, he was temperate in food and moderate in slumber. It was recorded of him that he had never sat more than one hour at meat in his own house, and that he never overslept the sunrise. After dinner he would converse with his friends, using commonly his native dialect of Bergamo, and entertaining the company now with stories of adventure, and now with pithy sayings. In another essential point he resembled his illustrious contemporary, the Duke of Urbino; for he was sincerely pious in an age which, however it preserved the decencies of ceremonial religion, was profoundly corrupt at heart. His principal lordships in the Bergamasque territory owed to his munificence their fairest churches and charitable institutions. At Martinengo, for example, he rebuilt and re-endowed two monasteries, the one dedicated to S. Chiara, the other to S. Francis. In Bergamo itself he founded an establishment named' La Pieta,' for the good purpose of dowering and marrying poor girls. This house he endowed with a yearly income of 3000 ducats. The Sulphur baths of Trescorio, at some distance from the city, were improved and opened to poor patients by a hospital which he provided. At Rumano he raised a church to S. Peter, and erected buildings of public utility, which on his death he bequeathed to the society of the Misericordia in that town. All the places of his jurisdiction owed to him such benefits as good water, new walls, and irrigation works. In addition to these munificent foundations must be mentioned the Basella, or Monastery of Dominican friars, which he established not far from Bergamo, upon the river Serio, in memory of his beloved daughter Medea. Last, not least, was the Chapel of S. John the Baptist, attached to the Church of S. Maria Maggiore, which he endowed with fitting maintenance for two priests and deacons.
The one defect acknowledged by his biographer was his partiality for women. Early in life he married Tisbe, of the noble house of the Brescian Martinenghi, who bore him one daughter, Caterina, wedded to Gasparre Martinengo. Two illegitimate daughters, Ursina and Isotta, were recognised and treated by him as legitimate. The first he gave in marriage to Gherardo Martinengo, and the second to Jacopo of the same family. Two other natural children, Doratina and Ricardona, were mentioned in his will: he left them four thousand ducats a piece for dowry. Medea, the child of his old age (for she was born to him when he was sixty), died before her father, and was buried, as we have seen, in the Chapel of Basella.
Throughout his life he was distinguished for great physical strength and agility. When he first joined the troop of Braccio, he could race, with his corselet on, against the swiftest runner of the army; and when he was stripped, few horses could beat him in speed. Far on into old age he was in the habit of taking long walks every morning for the sake of exercise, and delighted in feats of arms and jousting matches. 'He was tall, straight, and full of flesh, well proportioned, and excellently made in all his limbs. His complexion inclined somewhat to brown, but was coloured with sanguine and lively carnation. His eyes were black; in look and sharpness of light, they were vivid, piercing, and terrible. The outlines of his nose and all his countenance expressed a certain manly nobleness, combined with goodness and prudence.' Such is the portrait drawn of Colleoni by his biographer; and it well accords with the famous bronze statue of the general at Venice.
Colleoni lived with a magnificence that suited his rank. His favourite place of abode was Malpaga, a castle built by him at the distance of about an hour's drive from Bergamo. The place is worth a visit, though its courts and gates and galleries have now been turned into a monster farm, and the southern rooms, where Colleoni entertained his guests, are given over to the silkworms. Half a dozen families, employed upon a vast estate of the Martinengo family, occupy the still substantial house and stables. The moat is planted with mulberry-trees; the upper rooms are used as granaries for golden maize; cows, pigs, and horses litter in the spacious yard. Yet the walls of the inner court and of the ancient state rooms are brilliant with frescoes, executed by some good Venetian hand, which represent the chief events of Colleoni's life—his battles, his reception by the Signory of Venice, his tournaments and hawking parties, and the great series of entertainments with which he welcomed Christiern of Denmark. This king had made his pilgrimage to Rome and was returning westward, when the fame of Colleoni and his princely state at Malpaga induced him to turn aside and spend some days as the general's guest. In order to do him honour, Colleoni left his castle at the king's disposal and established himself with all his staff and servants in a camp at some distance from Malpaga. The camp was duly furnished with tents and trenches, stockades, artillery, and all the other furniture of war. On the king's approach, Colleoni issued with trumpets blowing and banners flying to greet his guest, gratifying him thus with a spectacle of the pomp and circumstance of war as carried on in Italy. The visit was further enlivened by sham fights, feats of arms, and trials of strength. When it ended, Colleoni presented the king with one of his own suits of armour, and gave to each of his servants a complete livery of red and white, his colours. Among the frescoes at Malpaga none are more interesting, and none, thanks to the silkworms rather than to any other cause, are fortunately in a better state of preservation, than those which represent this episode in the history of the Castle.