It is exceedingly probable, as Dante and Giovanni Villani show, that the city of Fiesole, being situate upon the summit of the mountain, in order that her markets might be more frequented, and afford greater accommodation for those who brought merchandise, would appoint the place in which to told them, not upon the hill, but in the plain, between the foot of the mountain and the river Arno. I imagine these markets to have occasioned the first erections that were made in those places, and to have induced merchants to wish for commodious warehouses for the reception of their goods, and which, in time, became substantial buildings. And afterward, when the Romans, having conquered the Carthaginians, rendered Italy secure from foreign invasion, these buildings would greatly increase; for men never endure inconveniences unless some powerful necessity compels them. Thus, although the fear of war induces a willingness to occupy places strong and difficult of access, as soon as the cause of alarm is removed, men gladly resort to more convenient and easily attainable localities. Hence, the security to which the reputation of the Roman republic gave birth, caused the inhabitants, having begun in the manner described, to increase so much as to form a town, this was at first called the Villa Arnina. After this occurred the civil wars between Marius and Sylla; then those of Cæsar, and Pompey; and next those of the murderers of Cæsar, and the parties who undertook to avenge his death. Therefore, first by Sylla, and afterward by the three Roman citizens, who, having avenged the death of Cæsar, divided the empire among themselves, colonies were sent to Fiesole, which, either in part or in whole, fixed their habitations in the plain, near to the then rising town. By this increase, the place became so filled with dwellings, that it might with propriety be enumerated among the cities of Italy.
There are various opinions concerning the derivation of the word Florentia. Some suppose it to come from Florinus, one of the principal persons of the colony; others think it was originally not Florentia, but Fluentia, and suppose the word derived from fluente, or flowing of the Arno; and in support of their opinion, adduce a passage from Pliny, who says, "the Fluentini are near the flowing of the Arno." This, however, may be incorrect, for Pliny speaks of the locality of the Florentini, not of the name by which they were known. And it seems as if the word Fluentini were a corruption, because Frontinus and Cornelius Tacitus, who wrote at nearly the same period as Pliny, call them Florentia and Florentini; for, in the time of Tiberius, they were governed like the other cities of Italy. Besides, Cornelius refers to the coming of ambassadors from the Florentines, to beg of the emperor that the waters of the Chiane might not be allowed to overflow their country; and it is not at all reasonable that the city should have two names at the same time. Therefore I think that, however derived, the name was always Florentia, and that whatever the origin might be, it occurred under the Roman empire, and began to be noticed by writers in the times of the first emperors.
When the Roman empire was afflicted by the barbarians, Florence was destroyed by Totila, king of the Ostrogoths; and after a period of two hundred and fifty years, rebuilt by Charlemagne; from whose time, till the year 1215, she participated in the fortune of the rest of Italy; and, during this period, first the descendants of Charles, then the Berengarii, and lastly the German emperors, governed her, as in our general treatise we have shown. Nor could the Florentines, during those ages, increase in numbers, or effect anything worthy of memory, on account of the influence of those to whom they were subject. Nevertheless, in the year 1010, upon the feast of St. Romolo, a solemn day with the Fiesolani, they took and destroyed Fiesole, which must have been performed either with the consent of the emperors, or during the interim from the death of one to the creation of his successor, when all assumed a larger share of liberty. But then the pontiffs acquired greater influence, and the authority of the German emperors was in its wane, all the places of Italy governed themselves with less respect for the prince; so that, in the time of Henry III. the mind of the country was divided between the emperor and the church. However, the Florentines kept themselves united until the year 1215, rendering obedience to the ruling power, and anxious only to preserve their own safety. But, as the diseases which attack our bodies are more dangerous and mortal in proportion as they are delayed, so Florence, though late to take part in the sects of Italy, was afterward the more afflicted by them. The cause of her first division is well known, having been recorded by Dante and many other writers; I shall, however, briefly notice it.
Among the most powerful families of Florence were the Buondelmonti and the Uberti; next to these were the Amidei and the Donati. Of the Donati family there was a rich widow who had a daughter of exquisite beauty, for whom, in her own mind, she had fixed upon Buondelmonti, a young gentleman, the head of the Buondelmonti family, as her husband; but either from negligence, or, because she thought it might be accomplished at any time, she had not made known her intention, when it happened that the cavalier betrothed himself to a maiden of the Amidei family. This grieved the Donati widow exceedingly; but she hoped, with her daughter's beauty, to disturb the arrangement before the celebration of the marriage; and from an upper apartment, seeing Buondelmonti approach her house alone, she descended, and as he was passing she said to him, "I am glad to learn you have chosen a wife, although I had reserved my daughter for you;" and, pushing the door open, presented her to his view. The cavalier, seeing the beauty of the girl, which was very uncommon, and considering the nobility of her blood, and her portion not being inferior to that of the lady whom he had chosen, became inflamed with such an ardent desire to possess her, that, not thinking of the promise given, or the injury he committed in breaking it, or of the evils which his breach of faith might bring upon himself, said, "Since you have reserved her for me, I should be very ungrateful indeed to refuse her, being yet at liberty to choose;" and without any delay married her. As soon as the fact became known, the Amidei and the Uberti, whose families were allied, were filled with rage, and having assembled with many others, connections of the parties, they concluded that the injury could not be tolerated without disgrace, and that the only vengeance proportionate to the enormity of the offence would be to put Buondelmonti to death. And although some took into consideration the evils that might ensue upon it, Mosca Lamberti said, that those who talk of many things effect nothing, using that trite and common adage, Cosa fatta capo ha. Thereupon, they appointed to the execution of the murder Mosca himself, Stiatti Uberti, Lambertuccio Amidei, and Oderigo Fifanti, who, on the morning of Easter day, concealed themselves in a house of the Amidei, situate between the old bridge and St. Stephen's, and as Buondelmonti was passing upon a white horse, thinking it as easy a matter to forget an injury as reject an alliance, he was attacked by them at the foot of the bridge, and slain close by a statue of Mars. This murder divided the whole city; one party espousing the cause of the Buondelmonti, the other that of the Uberti; and as these families possessed men and means of defense, they contended with each other for many years, without one being able to destroy the other.