Giangaleazzo Visconti (1351–1402) was the first Duke of Milan and ruled the city just before the beginning of the Renaissance. He is well known for his attempt to create a unified northern Italy by conquering the other cities in the valley of the Po. Although this attempt failed, he remains a figure of key importance in the history of late medieval Europe. This volume, which was originally published in 1941, constitutes the first full account of his life. Whilst the process of biography was rendered difficult by a lack of first-hand documentation - the carefully accumulated material in Giangaleazzo's chanceries was destroyed when the Castello of Milan was razed to the ground - an idea of his character was developed through the use of evidence from other government sources. The end product will be of value to anyone with an interest in Giangaleazzo and medieval European history.