The Ghibellines resumed power and undid many of the advances of the Guelphs, for example the demolition of hundreds of towers, homes, and palaces.

The fragility of their rule caused the Ghibellines to seek out an arbitrator in the form of Pope Clement IV, who openly favoured the Guelphs, and restored them to power.

The Florentine economy reached a zenith in the latter half of the 13th century, and its success was reflected by the building of the famed Palazzo della Signoria, designed by Arnolfo di Cambio.

A certain dissolute priest, called Neri Abati, prior of San Piero Scheraggio, false to his family and in concert with the Black chiefs, consented to set fire to the dwellings of his own kinsmen in Orto-san-Michele; the flames, assisted by faction, spread rapidly over the richest and most crowded part of Florence: shops, warehouses, towers, private dwellings and palaces, from the old to the new market-place, from Vacchereccia to Porta Santa Maria and the Ponte Vecchio, all was one broad sheet of fire: more than nineteen hundred houses were consumed; plunder and devastation revelled unchecked amongst the flames, whole races were reduced in one moment to beggary, and vast magazines of the richest merchandise were destroyed.

The Cavalcanti, one of the most opulent families in Florence, beheld their whole property consumed, and lost all courage; they made no attempt to save it, and, after almost gaining possession of the city, were finally overcome by the opposite faction.The golden florin of the Republic of Florence was the first European gold coin struck in sufficient quantities to play a significant commercial role since the 7th century.

While the banks perished, Florentine literature flourished, and Florence was home to some of the greatest writers in Italian history: Dante, Petrarch, and Boccaccio.

The ensuing collapse of the feudal system changed the social composition of Europe forever; it was one of the first steps out of the Middle Ages.

[16] The bank continued to exist (albeit in an extremely diminished form) until the time of Ferdinando II de'Medici in the 17th century.

During this period Florence, under the leadership of Maso degli Albizzi and Niccolò da Uzzano was involved in three wars with Milan (1390–92, 1397–98, 1400–02).

Pisa and Siena as well as a number of smaller cities submitted to Gian Galeazzo, while Lucca withdrew from the anti-Visconti league, with Bologna remaining the only major ally.

Since the Pisans did not intend to voluntarily submit to their long-time rivals, the army under Maso degli Albizzi took Pisa on 9 October 1406 after a long siege, that was accompanied by numerous atrocities.

Apart from war, Filippo Brunelleschi created the renowned dome of the Santa Maria del Fiore, which astounded contemporaries and modern observers alike.

He played a prominent role in the government of Florence until his exile in 1433, after a disastrous war with Tuscany's neighbour, the Republic of Lucca.

The Renaissance began during Cosimo's de facto rule of Florence, the seeds of which had arguably been laid before the Black Death tore through Europe.

This series of conflicts between the Venetian Republic and the Duchy of Milan for hegemony in Northern Italy lasted from 1423 to 1454 and involved a number of Italian states, that occasionally switched sides according to their changing interests.

Florentine trade interests made her support Sforza's Milan in the war against Venice, while the fall of Constantinople in 1453 dealt a blow to Venetian finances.

A number of them (Serragli, Baroncelli, Mancini, Vespucci, Gianni) were practically ruined and had to sell their properties, and those were acquired by Medici's partisans at bargain prices.

The opposition used partial relaxation of Medici control of the republic institutions[30] to demand political reforms, freedom of speech in the councils and a greater share in the decision-making.

Medici's party response was to use threats of force from private armies and Milanese troops and arranging a popular assembly dominated by Cosimo's supporters.

In his memoirs, Pius said that Cosimo "was considered the arbiter of war and peace, the regulator of law; less a citizen than master of his city.

[33] Piero's reign furthered the always fractious political divisions of Florence when he had called up huge debts owed to the Medici Bank.

Lorenzo had many children with his wife Clarice Orsini, including the future Pope Leo X and his eventual successor in Florence, Piero the Unfortunate.

The people blamed Savonarola for their woes, and he was tortured and executed in the Piazza della Signoria by being burned at the stake by Florentine authorities, in May 1498.

[43] Soderini was repudiated in September 1512, when Cardinal Giovanni de' Medici captured Florence with Papal troops during the War of the League of Cambrai.

[51] According to U.S. President and historian John Adams, "at this time the citizens of the state of Florence were in secret very discontented, because the Duke Lorenzo, desiring to reduce the government to the form of a principality, appeared to disdain to consult any longer with the magistrates and his fellow-citizens as he used to do, and gave audiences very seldom, and with much impatience; he attended less to the business of the city, and caused all public affairs to be managed by Messer Goro da Pistoia, his secretary.

"[51] In 1519, Lorenzo died from syphilis, shortly before his wife gave birth to Catherine de' Medici, the future Queen of France.

[52] Following the death of Lorenzo II, Cardinal Giulio de' Medici governed Florence until 1523, when he was elected Pope Clement VII.

"[51] Adams chronicles Cardinal Giulio as having "reduced the business of the magistrates, elections, customs of office, and the mode of expenditure of public money, in such a manner that it produced a great and universal joy among the citizens.

In alliance with Spain and the Holy Roman Empire, Cosimo defeated the Republic of Siena, which was allied with France, in the Battle of Marciano on 2 August 1554.

After Alessandro de' Medici was installed as the "Duke of the Florentine Republic" in 1530, in April 1532, Pope Clement VII convinced the Balía, Florence's ruling commission, to draw up a new constitution, which formally created a hereditary monarchy.