Background
He was the son of Matteo I Visconti and Bonacossa Borri.
He was the son of Matteo I Visconti and Bonacossa Borri.
He also was a military leader who fought against Florence, and used force to capture and hold other cities. Giovanni Visconti was elected archbishop by the Capitol of Milan in 1317, but Pope John XXII refused to confirm the election and instead raised Aircardus from Comodeia to that position. In 1331 he became bishop and lord of Novara, and in 1339, after Aicardus" death, he triumphantly entered Milan, although Pope Clement VI only issued a bull confirming him in the archbishopric in 1342.
Officially, he thus was Archbishop of Milan from 1342 to 1354.
The year after Luchino Visconti"s death in 1349, and with the approval of his relations, Giovanni Visconti assumed full lordship of Milan and began consolidating power in Lombardy and beyond. The same year, 1350, he obtained lordship over Bologna and placed in nephew, Bernabò, in charge of the city in 1351.
Afraid of his growing strength, in 1350 Florence organized a conference in Arezzo with a papal legate and representatives of other cities to form an alliance against Milan. Aware of these moves against him, Giovanni Visconti cultivated affection and alliance with the Ghibellines of Tuscany and Romagna.
In 1351, he sent troops from Milan and Bologna, and from allies in Faenza and Forlì, all led by Bernabò, to lay siege to Imola.
With war occurring in the Romagna region, Giovanni Visconti was able to lull the Florentines into believing that he had no intentions towards them. However, he then had many leading Bolognese citizens arrested and tortured, and extracted confessions from them of a conspiracy with Florence to overthrow his rule. He used this as a justification of war against Florence and the Guelphs of Tuscany.
In 1352, Giovanni Visconti became lord of Genoa, and in the following year, he added Novara.
In 1353, Petrarch visited as his guest. Giovanni Visconti died 5 October 1354.