amongst German cities. Charles was the patron of the Nuremberg Frauenkirche, built between 1352 and 1362 (the architect was likely Peter Parler), where the imperial court worshipped during its stays in Nuremberg. Charles's imperial policy was focused on the dynastic sphere and abandoned the lofty ideal of the Empire as a universal monarchy of Christendom. In 1353, he granted the Duchy of Luxembourg to his half-brother, Wenceslaus. He concentrated his energies chiefly on the economic and intellectual development of Bohemia, where he founded the university in 1348 and encouraged the early humanists. He corresponded with Petrarch and invited him to visit the royal residence in Prague, whilst the Italian hoped – to no avail – to see Charles move his residence to Rome and reawaken tradition of the Roman Empire. Charles's sister Bona married the eldest son of Philip VI of France, the future John II of France, in 1335. Thus, Charles was the maternal uncle of Charles V of France, who solicited his relative's advice at Metz in 1356 during the Parisian Revolt. This family connection was celebrated publicly when Charles made a solemn visit to his nephew in 1378, just months before his death. A detailed account of the occasion, enriched by many splendid miniatures, can be found in Charles V's copy of the Grandes Chroniques de France. Castles Castles built or established by Charles IV: Karlštejn, 1348–1355 in Central Bohemian Region for safekeeping the Imperial Regalia, especially the Imperial Crown of the Holy Roman Empire (later the Czech Crown Jewels were also kept there) Kašperk (Karlsberg), 1356 in Kašperské Hory in Plzeň Region Lauf (Wenzelsburg) – built on the way connecting Prague and Nuremberg in Bohemian Palatinate, inside survived 112 coats of arms of the Bohemian Kingdom Montecarlo in Italy Radyně (Karlskrone) – around 1360 in Plzeň Region Hrádek u Purkarce (Karlshaus) – around 1357 Tepenec (Twingenberg, Karlsburg) in Jívová in Olomouc Region Karlsfried Places named after Charles IV Czech Republic Karlovy Vary, a spa city Karlštejn, a town beyond the eponymous castle Charles Bridge (Karlův most), Prague Charles University (Univerzita Karlova), Prague Multiple squares – Charles Square (Karlovo náměstí) in Prague and others, for example in Brno, Kolín, Mělník etc. Multiple streets Italy Montecarlo (Charles's Mountain), a municipality Other The 100-Czech koruna banknote 16951 Carolus Quartus, an asteroid Family Genealogy Marriages and children Charles was married four times. His first wife was Blanche of Valois (1316–1348),