In the 13th century, much of Europe experienced strong economic growth. The trade routes of the Italian states linked with those of established Mediterranean ports and eventually the Hanseatic League of the Baltic and northern regions of Europe to create a network economy in Europe for the first time since the 4th century. The city-states of Italy expanded greatly during this period and grew in power to become de facto fully independent of the Holy Roman Empire; outside European powers kept their armies out of Italy.
During this period, the modern commercial infrastructure developed, with the creation in Italy of the double-entry book-keeping, joint stock companies, an international banking system, a systematized foreign exchange market, insurance, and government debt. Florence became the centre of this financial industry and the gold florin became the main currency of international trade. The Republic of Venice and the Republic of Genova dominated the trade in the Mediterranean sea.
Many argue that the ideas that characterized the Renaissance had their origin in late 13th century Florence, in particular with the writings of Dante Alighieri (1265-1321)  as well as the painting of Giotto (1267-1337).
The thirteenth-century Italian literary revolution helped set the stage for the Renaissance. Prior to the Renaissance, the Italian language was not the literary language in Italy. It was only in the 13th century that Italian authors began writing in their native language rather than Latin, French, or Provençal. The 1250s saw a major change in Italian poetry as the Dolce Stil Novo (Sweet New Style, which emphasized Platonic rather than courtly love) came into its own, pioneered by poets like Guittone d'Arezzo and Guido Guinizelli. Especially in poetry, major changes in Italian literature had been taking place decades before the Renaissance truly began.
With the printing of books initiated in Venice by Aldus Manutius, an increasing number of works began to be published in the Italian language in addition to the flood of Latin and Greek texts that constituted the mainstream of the Italian Renaissance.
This is not to say that no religious works were published in this period: Dante Alighieri's The Divine Comedy reflects a distinctly medieval world view. This masterpiece helped establish the Tuscan language, in which it is written (also in most present-day Italian-market editions), as the standardized Italian language.
The art of the region of Tuscany (and northern Italy) in the second half of the 13th century was dominated by two masters: Cimabue of Florence and Duccio of Siena. Their commissions were mostly religious paintings, several of them being very large altarpieces showing the Madonna and Child. These two painters, with their contemporaries, Guido of Siena, Coppo di Marcovaldo and the mysterious painter upon whose style the school may have originated, the so-called Master of St Bernardino, all worked in a manner that was highly formalised and dependent upon the ancient tradition of icon painting. Cimabue and Duccio both took steps in the direction of greater naturalism, as did their contemporary, Pietro Cavallini of Rome.
Giotto (born in 1266) by tradition a shepherd boy from the hills north of Florence, became Cimabue's apprentice and emerged as the most outstanding painter of his time. Giotto, possibly influenced by Pietro Cavallini and other Roman painters, did not base the figures that he painted upon any painterly tradition, but upon the observation of life. Unlike those of his Byzantine-related contemporaries, Giotto's figures are solidly three-dimensional; they stand squarely on the ground, have discernible anatomy and are clothed in garments with weight and structure. But more than anything, what set Giotto's figures apart from those of his contemporaries are their emotions. In the faces of Giotto's figures are joy, rage, despair, shame, spite and love. The cycle of frescoes of the Life of Christ and the Life of the Virgin that he painted in the Scrovegni Chapel in Padua set a new standard for narrative pictures. His Ognissanti Madonna hangs in the Uffizi Gallery, Florence, in the same room as Cimabue's Santa Trinita Madonna and Duccio's Ruccellai Madonna where the stylistic comparisons between the three can easily be made. One of the features apparent in Giotto's work is his observation of naturalistic perspective. He is regarded as the herald of the Renaissance.
In the early Duecento in Italy started to appear the Italian Gothic. The first Italian Gothic edifices were Cistercian abbeys. They spread in the whole Italian territory, often adapting the construction techniques to the local traditions. There were in fact brickwork edifices in the Pianura Padana, while stone prevailed in central Italy and Tuscany. In the latter was sometimes present the by-chrome wall decoration from the local Romanesque tradition.
The most important edifices include the Chiaravalle Abbey in northern Italy and the Casamari Abbey in central Italy. Among the non-Cistercian buildings of this century which were influenced by the Gothic style, though still presenting important Romanesque features, are the Parma Baptistery by Benedetto Antelami and the church of Sant'Andrea in Vercelli, also featuring Antelami's influences.
This century saw the construction of numerous Gothic buildings for the Mendicant Orders. The most important ones include:
Also notable is the civil and military construction program promoted by Emperor and King of Sicily Frederick II of Hohenstaufen in southern Italy at the beginning of the century. The most important works promoted by him include:
In this period some cathedrals were also constructed or finished, such as the Siena Cathedral.
Vita di San Francesco, of Bonaventura Berlinghieri, 1235
Cross of Santa Croce, of Cimabue
Giotto: St. Francis' Sermon to the Birds
Basilica of San Francesco of Assisi: Nave of the upper basilica (built 1228-1253)
Pulpito a Siena, by Nicola Pisano
Guido da Siena's "Fuga in Egitto"