wealthy and aristocratic Florentine citizen who was the leader of a “popular” movement in the 1290s and is known as the promulgator of the Ordinances of Justice (January 1293), the basis of the constitution of Florence.

A member of the powerful Calimala guild of merchants and bankers, Giano abandoned his own “magnate” class of established wealth to head the popular faction in 1292–93. The Ordinances of Justice, drawn up at his instigation, attacked the privileges of the magnates and gave the minor guilds a share in the government. Not himself a member of the priorate (executive body) that passed the ordinances, Giano served in the subsequent one (Feb. 15, 1293) that implemented them. Although his two-month term expired in April 1293, Giano continued to exercise indirect control over the government in the following two years, arousing the hostility of the magnates, who started a whispering campaign against him. In January 1295, a case tried under the Ordinances of Justice involving the murder of a commoner by a noble, Corso Donati (Donati, Corso), led to a mob attack on the palace of the podestà (chief magistrate). A new priorate elected the following month accused Giano of causing the disorder. Refusing to appear before the priorate, Giano left Florence. He was immediately condemned, under his own Ordinances of Justice, to death and confiscation of goods. He died an exile in France some 10 years later.