The book by the famous French medievalist R. Casel is dedicated to the life and deeds of John of Luxembourg (1296-1346), king of the Czech Republic, who went down in history as a monarch-knight, famous for the fact that already being completely blind, he entered the battlefield and fought on par with the rest. He died in this battle, making his name synonymous with senseless heroism. This is the textbook, common view of the figure of the Czech sovereign. The biography written by R. Casel offers us a different image of John of Luxembourg: a brilliant knight and successful commander, a deft and active diplomat, who for many years played a key role in European politics, who traveled vast spaces from France to Lithuania, from Flanders to Italy, the founder Czech Luxembourg dynasty. Using the example of John, the author shows how a personality could influence the socio-political changes that took place in the first half of the 14th century. in Western and Central Europe.