We know quite a bit about the early life of Besson due to the efforts of Eugenie Droz. Ramelli is still a mystery. In his preface, he extolles the virtues of his former patron, Gian Giacomo Medici di Marignano. So who was El Medeghino? The web seems to have forgotten.
Project Guttenburg provides some dusty details. Consider this excerpt from John Addington Symonds's 1914 work "Sketches and Studies in Italy and Greece" (London: John Murray; http://www.gutenberg.org/files/14972/14972-h/14972-h.htm).
While the people of Como were thus straining every nerve to complete a pious work, which at the same time is one of the most perfect masterpieces of Italian art, their lovely lake was turned into a pirate's stronghold, and its green waves stained with slaughter of conflicting navies. So curious is this episode in the history of the Larian lake that it is worth while to treat of it at some length. Moreover, the lives of few captains of adventure offer matter more rich in picturesque details and more illustrative of their times than that of Gian Giacomo de' Medici, the Larian corsair, long known and still remembered as Il Medeghino. He was born in Milan in 1498, at the beginning of that darkest and most disastrous period of Italian history, when the old fabric of social and political existence went to ruin under the impact of conflicting foreign armies. He lived on until the year 1555, witnessing and taking part in the dismemberment of the Milanese Duchy, playing a game of hazard at high stakes for his own profit with the two last Sforzas, the Empire, the French, and the Swiss. At the beginning of the century, while he was still a youth, the rich valley of the Valtelline, with Bormio and Chiavenna, had been assigned to the Grisons. The Swiss Cantons at the same time had possessed themselves of Lugano and Bellinzona. By these two acts of robbery the mountaineers tore a portion of its fairest territory from the Duchy; and whoever ruled in Milan, whether a Sforza, or a Spanish viceroy, or a French general, was impatient to recover the lost jewel of the ducal crown. So much has to be premised, because the scene of our hero's romantic adventures was laid upon the borderland between the Duchy and the Cantons. Intriguing at one time with the Duke of Milan, at another with his foes the French or Spaniards, Il Medeghino found free scope for his peculiar genius in a guerilla warfare, carried on with the avowed purpose of restoring the Valtelline to Milan. To steer a plain course through that chaos of politics, in which the modern student, aided by the calm clear lights of history and meditation, cannot find a clue, was of course impossible for an adventurer whose one aim was to gratify his passions and exalt himself at the expense of others. It is therefore of little use to seek motives of statecraft or of patriotism in the conduct of Il Medeghino. He was a man shaped according to Machiavelli's standard of political morality—self-reliant, using craft and force with cold indifference to moral ends, bent only upon wringing for himself the largest share of this world's power for men who, like himself, identified virtue with unflinching and immitigable egotism.
Il Medeghino's father was Bernardo de' Medici, a Lombard, who neither claimed nor could have proved cousinship with the great Medicean family of Florence. His mother was Cecilia Serbelloni. The boy was educated in the fashionable humanistic studies, nourishing his young imagination with the tales of Roman heroes. The first exploit by which he proved his virtù, was the murder of a man he hated, at the age of sixteen. This 'virile act of vengeance,' as it was called, brought him into trouble, and forced him to choose the congenial profession of arms. At a time when violence and vigour passed for manliness, a spirited assassination formed the best of introductions to the captains of mixed mercenary troops. Il Medeghino rose in favour with his generals, helped to reinstate Francesco Sforza in his capital, and, returning himself to Milan, inflicted severe vengeance on the enemies who had driven him to exile. It was his ambition, at this early period of his life, to be made governor of the Castle of Musso, on the Lake of Como. While fighting in the neighbourhood, he had observed the unrivalled capacities for defence presented by its site; and some pre-vision of his future destinies now urged him to acquire it, as the basis for the free marauding life he planned. The headland of Musso lies about halfway between Gravedona and Menaggio, on the right shore of the Lake of Como. Planted on a pedestal of rock, and surmounted by a sheer cliff, there then stood a very ancient tower, commanding this promontory on the side of the land. Between it and the water the Visconti, in more recent days, had built a square fort; and the headland had been further strengthened by the addition of connecting walls and bastions pierced for cannon. Combining precipitous cliffs, strong towers, and easy access from the lake below, this fortress of Musso was exactly the fit station for a pirate. So long as he kept the command of the lake, he had little to fear from land attacks, and had a splendid basis for aggressive operations. Il Medeghino made his request to the Duke of Milan; but the foxlike Sforza would not grant him a plain answer. At length he hinted that if his suitor chose to rid him of a troublesome subject, the noble and popular Astore Visconti, he should receive Musso for payment. Crimes of bloodshed and treason sat lightly on the adventurer's conscience. In a short time he compassed the young Visconti's death, and claimed his reward. The Duke despatched him thereupon to Musso, with open letters to the governor, commanding him to yield the castle to the bearer. Private advice, also entrusted to Il Medeghino, bade the governor, on the contrary, cut the bearer's throat. The young man, who had the sense to read the Duke's letter, destroyed the secret document, and presented the other, or, as one version of the story goes, forged a ducal order in his own favour. At any rate, the castle was placed in his hands; and affecting to know nothing of the Duke's intended treachery, Il Medeghino took possession of it as a trusted servant of the ducal crown.
As soon as he was settled in his castle, the freebooter devoted all his energies to rendering it still more impregnable by strengthening the walls and breaking the cliffs into more horrid precipices. In this work he was assisted by his numerous friends and followers; for Musso rapidly became, like ancient Rome, an asylum for the ruffians and outlaws of neighbouring provinces. It is even said that his sisters, Clarina and Margherita, rendered efficient aid with manual labour. The mention of Clarina's name justifies a parenthetical side-glance at Il Medeghino's pedigree, which will serve to illustrate the exceptional conditions of Italian society during this age. She was married to the Count Giberto Borromeo, and became the mother of the pious Carlo Borromeo, whose shrine is still adored at Milan in the Duomo. Il Medeghino's brother, Giovan Angelo, rose to the Papacy, assuming the title of Pius IV. Thus this murderous marauder was the brother of a Pope and the uncle of a Saint; and these three persons of one family embraced the various degrees and typified the several characters which flourished with peculiar lustre in Renaissance Italy—the captain of adventure soaked in blood, the churchman unrivalled for intrigue, and the saint aflame with holiest enthusiasm. Il Medeghino was short of stature, but well made and powerful; broad-chested; with a penetrating voice and winning countenance. He dressed simply, like one of his own soldiers; slept but little; was insensible to carnal pleasure; and though he knew how to win the affection of his men by jovial speech, he maintained strict discipline in his little army. In all points he was an ideal bandit chief, never happy unless fighting or planning campaigns, inflexible of purpose, bold and cunning in the execution of his schemes, cruel to his enemies, generous to his followers, sacrificing all considerations, human and divine, to the one aim of his life, self-aggrandisement by force and intrigue. He knew well how to make himself both feared and respected. One instance of his dealing will suffice. A gentleman of Bellano, Polidoro Boldoni, in return to his advances, coldly replied that he cared for neither amity nor relationship with thieves and robbers; whereupon Il Medeghino extirpated his family, almost to a man.
Soon after his settlement in Musso, Il Medeghino, wishing to secure the gratitude of the Duke, his master, began war with the Grisons. From Coire, from the Engadine, and from Davos, the Alpine pikemen were now pouring down to swell the troops of Francis I.; and their road lay through the Lake of Como. Il Medeghino burned all the boats upon the lake, except those which he took into his own service, and thus made himself master of the water passage. He then swept the 'length of lordly Lario' from Colico to Lecco, harrying the villages upon the shore, and cutting off the bands of journeying Switzers at his pleasure. Not content with this guerilla, he made a descent upon the territory of the Trepievi, and pushed far up towards Chiavenna, forcing the Grisons to recall their troops from the Milanese. These acts of prowess convinced the Duke that he had found a strong ally in the pirate chief. When Francis I. continued his attacks upon the Duchy, and the Grisons still adhered to their French paymaster, the Sforza formally invested Gian Giacomo de' Medici with the perpetual governorship of Musso, the Lake of Como, and as much as he could wrest from the Grisons above the lake. Furnished now with a just title for his depredations, Il Medeghino undertook the siege of Chiavenna. That town is the key to the valleys of the Splügen and Bregaglia. Strongly fortified and well situated for defence, the burghers of the Grisons well knew that upon its possession depended their power in the Italian valleys. To take it by assault was impossible, Il Medeghino used craft, entered the castle, and soon had the city at his disposition. Nor did he lose time in sweeping Val Bregaglia. The news of this conquest recalled the Switzers from the Duchy; and as they hurried homeward just before the battle of Pavia, it may be affirmed that Gian Giacomo de' Medici was instrumental in the defeat and capture of the French King. The mountaineers had no great difficulty in dislodging their pirate enemy from Chiavenna, the Valtelline, and Val Bregaglia. But he retained his hold on the Trepievi, occupied the Valsassina, took Porlezza, and established himself still more strongly in Musso as the corsair monarch of the lake.
The tyranny of the Sforzas in Milan was fast going to pieces between France and Spain; and in 1526 the Marquis of Pescara occupied the capital in the name of Charles V. The Duke, meanwhile, remained a prisoner in his Castello. Il Medeghino was now without a master; for he refused to acknowledge the Spaniards, preferring to watch events and build his own power on the ruins of the dukedom. At the head of 4,000 men, recruited from the lakes and neighbouring valleys, he swept the country far and wide, and occupied the rich champaign of the Brianza. He was now lord of the lakes of Como and Lugano, and absolute in Lecco and the adjoining valleys. The town of Como itself alone belonged to the Spaniards; and even Como was blockaded by the navy of the corsair. Il Medeghino had a force of seven big ships, with three sails and forty-eight oars, bristling with guns and carrying marines. His flagship was a large brigantine, manned by picked rowers, from the mast of which floated the red banner with the golden palle of the Medicean arms. Besides these larger vessels, he commanded a flotilla of countless small boats. It is clear that to reckon with him was a necessity. If he could not be put down with force, he might be bought over by concessions. The Spaniards adopted the second course, and Il Medeghino, judging that the cause of the Sforza family was desperate, determined in 1528 to attach himself to the Empire. Charles V. invested him with the Castle of Musso and the larger part of Como Lake, including the town of Lecco. He now assumed the titles of Marquis of Musso and Count of Lecco: and in order to prove his sovereignty before the world, he coined money with his own name and devices.
It will be observed that Gian Giacomo de' Medici had hitherto acted with a single-hearted view to his own interests. At the age of thirty he had raised himself from nothing to a principality, which, though petty, might compare with many of some name in Italy—with Carpi, for example, or Mirandola, or Camerino. Nor did he mean to remain quiet in the prime of life. He regarded Como Lake as the mere basis for more arduous undertakings. Therefore, when the whirligig of events restored Francesco Sforza to his duchy in 1529, Il Medeghino refused to obey his old lord. Pretending to move under the Duke's orders, but really acting for himself alone, he proceeded to attack his ancient enemies, the Grisons. By fraud and force he worked his way into their territory, seized Morbegno, and overran the Valtelline. He was destined, however, to receive a serious check. Twelve thousand Switzers rose against him on the one hand, on the other the Duke of Milan sent a force by land and water to subdue his rebel subject, while Alessandro Gonzaga marched upon his castles in the Brianza. He was thus assailed by formidable forces from three quarters, converging upon the Lake of Como, and driving him to his chosen element, the water. Hastily quitting the Valtelline, he fell back to the Castle of Mandello on the lake, collected his navy, and engaged the ducal ships in a battle off Menaggio. In this battle he was worsted. But he did not lose his courage. From Bellagio, from Varenna, from Bellano he drove forth his enemies, rolled the cannon of the Switzers into the lake, regained Lecco, defeated the troops of Alessandro Gonzaga, and took the Duke of Mantua prisoner. Had he but held Como, it is probable that he might have obtained such terms at this time as would have consolidated his tyranny. The town of Como, however, now belonged to the Duke of Milan, and formed an excellent basis for operations against the pirate. Overmatched, with an exhausted treasury and broken forces, Il Medeghino was at last compelled to give in. Yet he retired with all the honours of war. In exchange for Musso and the lake, the Duke agreed to give him 35,000 golden crowns, together with the feud and marquisate of Marignano. A free pardon was promised not only to himself and his brothers, but to all his followers; and the Duke further undertook to transport his artillery and munitions of war at his own expense to Marignano. Having concluded this treaty under the auspices of Charles V. and his lieutenant, Il Medeghino, in March 1532, set sail from Musso, and turned his back upon the lake for ever. The Switzers immediately destroyed the towers, forts, walls, and bastions of the Musso promontory, leaving in the midst of their ruins the little chapel of S. Eufemia.
Gian Giacomo de' Medici, henceforth known to Europe as the Marquis of Marignano, now took service under Spain; and through the favour of Anton de Leyva, Viceroy for the Duchy, rose to the rank of Field Marshal. When the Marquis del Vasto succeeded to the Spanish governorship of Milan in 1536, he determined to gratify an old grudge against the ex-pirate, and, having invited him to a banquet, made him prisoner. II Medeghino was not, however, destined to languish in a dungeon. Princes and kings interested themselves in his fate. He was released, and journeyed to the court of Charles V. in Spain. The Emperor received him kindly, and employed him first in the Low Countries, where he helped to repress the burghers of Ghent, and at the siege of Landrecy commanded the Spanish artillery against other Italian captains of adventure: for, Italy being now dismembered and enslaved, her sons sought foreign service where they found best pay and widest scope for martial science. Afterwards the Medici ruled Bohemia as Spanish Viceroy; and then, as general of the league formed by the Duke of Florence, the Emperor, and the Pope to repress the liberties of Tuscany, distinguished himself in that cruel war of extermination, which turned the fair Contado of Siena into a poisonous Maremma. To the last Il Medeghino preserved the instincts and the passions of a brigand chief. It was at this time that, acting for the Grand Duke of Tuscany, he first claimed open kinship with the Medici of Florence. Heralds and genealogists produced a pedigree, which seemed to authorise this pretension; he was recognised, together with his brother, Pius IV., as an offshoot of the great house which had already given Dukes to Florence, Kings to France, and two Popes to the Christian world. In the midst of all this foreign service he never forgot his old dream of conquering the Valtelline; and in 1547 he made proposals to the Emperor for a new campaign against the Grisons. Charles V. did not choose to engage in a war, the profits of which would have been inconsiderable for the master of half the civilised world, and which might have proved troublesome by stirring up the tameless Switzers. Il Medeghino was obliged to abandon a project cherished from the earliest dawn of his adventurous manhood.
When Gian Giacomo died in 1555, his brother Battista succeeded to his claims upon Lecco and the Trepievi. His monument, magnificent with five bronze figures, the masterpiece of Leone Lioni, from Menaggio, Michelangelesque in style, and of consummate workmanship, still adorns the Duomo of Milan. It stands close by the door that leads to the roof. This mausoleum, erected to the memory of Gian Giacomo and his brother Gabrio, is said to have cost 7800 golden crowns. On the occasion of the pirate's funeral the Senate of Milan put on mourning, and the whole city followed the great robber, the hero of Renaissance virtù, to the grave.
Between the Cathedral of Como and the corsair Medeghino there is but a slight link. Yet so extraordinary were the social circumstances of Renaissance Italy, that almost at every turn, on her seaboard, in her cities, from her hill-tops, we are compelled to blend our admiration for the loveliest and purest works of art amid the choicest scenes of nature with memories of execrable crimes and lawless characters. Sometimes, as at Perugia, the nexus is but local. At others, one single figure, like that of Cellini, unites both points of view in a romance of unparalleled dramatic vividness. Or, again, beneath the vaults of the Certosa, near Pavia, a masterpiece of the serenest beauty carries our thoughts perforce back to the hideous cruelties and snake-like frauds of its despotic founder. This is the excuse for combining two such diverse subjects in one study.Not bad. Addington seems to miss some details related to what happened between 1547 and 1555. He apparently did some bloody work in the service of Charles V and Grand Duke Cosimo (incidently, his brother the Pope spent a good deal of money plastering those same Medici arms around Rome). A9 produced some information on his exploits during this time, particularly in besieging Sienna. According to a work called "Tchay and Chianti" by one Welbore St. Claire Baddeley, Il Medeghino put at least 5000 to death: "he destroyed many a wretched peasant with his iron staff, and scarcely was there a tree far or near upon which he had not caused some one to be hanged." (p. 194) It's unclear what source Baddeley was using.
The 1911 edition of the Encyclopedia Britannica has another description (http://www.1911encyclopedia.org/Siena):
"The government was now reconstituted under the protection of the French agents; the balia was abolished, its very name having been rendered odious by the tyranny of Spain, and was replaced by a similar magistracy styled capitani del popolo e reggimento. Siena exulted in her recovered freedom; but her sunshine was soon clouded. First, the emperor's wrath was stirred by the influence of France in the counsels of the republic; then Cosimo, who was no less jealous of the French, conceived the design of annexing Siena to his own dominions. The first hostilities of the imperial forces in Val di Chiana (1552-1553) did little damage; but when Cosimo took the field with an army commanded by the marquis of Marignano the ruin of Siena was at hand. On 26th January Marignano captured the forts of Porta Camollia (which the whole population of Siena, including the women, had helped to construct) and invested the city. On the 2nd of August of the same year, at Marciano in Val di Chiana, he won a complete victory over the Sienese and French troops under Piero Strozzi, the Florentine exile and marshal of France. Meanwhile Siena was vigorously besieged, and its inhabitants, sacrificing everything for their beloved city, maintained a most heroic defence. A glorious record of their sufferings is to be found in the Diary of Sozzini, the Sienese historian, and in the Commentaries of Blaise de Monluc, the French representative in Siena. But in April 1555 the town was reduced to extremity and was forced to capitulate to the emperor and the duke. On 21st April the Spanish troops entered the gates; thereupon many patriots abandoned the city and, taking refuge at Montalcino, maintained there a shadowy form of republic until 1559.
Cosimo I. de' Medici being granted the investiture of the Sienese state by the patent of Philip II. of Spain, dated 3rd July 1557, took formal possession of the city on the 19th of the same month. A lieutenant-general was appointed as representative of his authority; the council of the balia was reconstituted with twenty members chosen by the duke; the consistory and the general council were left in existence but deprived of their political autonomy. Thus Siena was annexed to the Florentine state under the same ruler and became an integral part of the grand-duchy of Tuscany. Nevertheless it retained a separate administration for more than two centuries, until the general reforms of the grand-duke Pietro Leopoldo, the French domination, and finally the restoration swept away all differences between the Sienese and Florentine systems of government. In 1859 Siena was the first Tuscan city that voted for annexation to Piedmont and the monarchy of Victor Emmanuel II., this decision (voted 26th June) being the initial step towards the unity of Italy."
So how did Ramelli end up in France? Did he fight in the Wars of Religion? What happened during that gap between 1555 and 1572? How did he end up in France?
UPDATE (December 1, 2006). I found some additional information in "Firearms and Fortifications," a remarkable work by Pepper and Adams. In their detailed account of the siege they note that the Marquis led the attacking forces from 1554 to 1555. The also note that the Marquis was particularly brutal in his treatment of fleeing Sienese: defenders were hung, peasants were sent to the galleys, and the nobility was ransomed. The aftermath of the seige led to a boom in local fortification continuing through the construction of Peruzzi's citadel, started in 1561.
Pepper, S. and Nicholas Adams. 1986. Firearms and fortifications: military architecture and siege warfare in sixteenth-century Siena. University of Chicago Press.