The Czech King and Roman Emperor Charles IV (Karel IV.) was a mighty ruler. He beautified the residential seat – Prague Castle, and Prague, which had become the main centre of the Holy Roman Empire, in such a way as to represent its status. However none of the country royal fortresses complied sufficiently to his ideas about a safe place for the Imperial crown jewels and treasures, nor were they on a level of a Roman Imperial residence. Therefore he ordered the building of a new castle in the year 1348.

It was founded not far from Prague on a protected, and considering the military techniques, unassailable spot, on a secluded rock surrounded by five hills. It is not impossible, that he also chose this location above the valley of the river Berounka, because he spent a part of his not very happy childhood in the nearby fortress Krivoklát, where he used to reside too as a viceroy with his first spouse Blanche de Valois. He entrusted the Karlstejn building to Matthias of Arras, whose successor was Peter Parler. Except for the decoration of the interior, the castle was finished in the year 1357.

The entrance gate with the Vorsilská Tower is built in such a way, that everybody, who went into the castle, would be seen by the guard in the main tower. The first yard was only for communication and defense purposes. The second gate leads into the yard where the viscount used to be and where the men, who served at the castle, were quartered. From this yard, on the right, stairs lead up to an important facility – the castle well, covered by a tower. It is 84 metres deep, cut out of the rock.

The water was drawn from it by means of a wooden treadwheel. It took more than ten minutes before the pail appeared at the top of the well. A gate leads from the second yard to the actual heart of the castle. At the front of a little yard stands the residential palace, at the end of which is a semi-circular tower. In the palace are the courtier rooms, rooms for the Emperor’s armed guard, the Imperial work and reception room and the bedroom. From this leads a spiral staircase to the third floor, where the Empress lived with her servants.

On the rock above the palace are two square towers. With these Karlstejn is distinguished from other Central-European castles, which normally have only one, usually round, tower. In the lower, which is called Church Tower, on the second floor is the chapel of the Assumption of the Virgin Mary. In this chapel are beautiful, preserved wall paintings, with which the whole castle used to be decorated. The series of the Apocalypse of St. John is a part of it, but more important are the “Relic Pictures” in which Charles is painted at life size. In the first picture he receives a relic of the cross and two thorns of Christ’s crown from the French dauphin.

The second picture seems to represent the Hungarian King Louis the Great, who hands over some more splinters of Christ’s cross. In the third picture Charles forms the relics into the shape of a precious cross. The last part of the castle’s interior is the big tower formed by massive walls. On its second floor is a sanctuary, which is the most beautiful place in the castle. It is the chapel of the Holy Cross. It was designed as a safe for the Imperial crown jewels and the holy relics, which Charles collected avidly. At one time the Czech crown jewels were kept there too. A niche in the altar served for this purpose, enclosed by gilded bars. The chapel occupies the whole floor. The space is partioned by gilded lattice. It is in laid with shimmering semi-precious stones, predominantly red in colour. Most are placed in such a way, that they form a cross. The vault is covered with gilded plaster and glass basins covering gilded foliage. Together with a silver moon and a golden sun it creates an illusion of the sky full of stars.

The upper part of the walls are covered with valuable pictures on wood, painted in the atelier of master Theodor. Most of the pictures are portraits of church representatives. In the window arches are also frescos. In Charles’ period, because of the rare relics of the Holy Cross, only dignitaries with pontific rights were allowed to minister the services there. In order not to disturb the sacredness of the place, Charles made the regulation that: in the tower of the castle Karlstejn, in which the mentioned chapel is, or in any chamber of this tower, it is forbidden for anyone to sleep or lie with a woman, whether it be his lawful wife or not. From this emerged the legend, that no woman had access to the castle.