The
building of the castle did not
take long, seven years elapsing from the time of its foundation in 1348.
Documents exist testifying to Charles's sojourn at Karlstejn in 1355
and to the first burggrave. The burggrave's Palace and at the same time
also the Imperial Palace were the first to be built, because Charles
IV wanted to personally observe and supervise the construction of the
other parts of the castle as well as the decorating of their interiors.
On 27 March, 1357 the chapel in the Marian Tower was consecrated to
Our Lady along with a small chapel which was later called St. Catherine's.
The group of relics was situated here in the period preceding the completion
of the decoration of the Chapel of the Holy Rood.
The
person of the main architect connected with the construction
of the castle has never been explicitly documented. However, the names
of some of the artists who participated in the painted decoration of
the interiors are known, in particular, for example, Mikulas Wurmser
of Strassbourg and Master Theodoric. The gallery of panel paintings
in the Chapel of the Holy Rood from the latter's workshop aroused admiration
already at the time of Charles IV.
The
decoration of the walls of Karlstejn Castle began in St. Nicholas's
Chapel in the Imperial Palace in 1353 and continued in a hall on the
second floor of the palace, where Charles IV's family tree was portrayed.
St. Nicholas's Chapel was decorated with murals showing scenes of the
miracle with the relics of St. Nicholas in St. Francis's Monastery in
Prague. However, this wall decoration has not been preserved and neither
has that in the hall, but thanks to reports in chronicies we at least
know their themes. The main reception hall was decorated with portraits
of Charles IV's real and fictive ancestors and they are alleged to be
the work of the Master of the Family Tree.

The
Chapel of Our Lady is still adorned with wall paintings, which
are attributed to Mikulas Wurmser of Strassbourg. Adjoining it is Charles
IV's private oratory, likewise decorated with murals as well as incrustations.
This chapel was later consecrated to St. Catherine. In the course of
the decoration of the castle the greatest attention was devoted to the
Great Tower. In a later phase even the staircase leading to the Chapel
of the Holy Rood was provided with wall paintings with historical themes
celebrating the lives of two Czech saints from the Premyslid dynasty
- St. Wenceslas and St. Ludmila.

In
the Chapel of the Holy Rood court artists tried to express Holy
Jerusalem by means of allegories and thus an interior originated which
is a unique work of art still today. The gilded ceiling of the chapel
is covered with glass lenses which glow in the form of stars, creating
a starry sky supplemented with a Sun and a Moon. The walls of the chapel
were decorated with 130 panel paintings from Master Theodoric's workshop.
Placed in bands above each other, they portray heavenly warriors to
guard the imperial treasure. The selection and arrangement of the paintings
were subordinated to a strict hierarchy, all the figures of saints and
martyrs being portrayed in an order corresponding to the rhythm of the
litany to all saints. On the vaults of the window niches wall paintings
originated which included the theme The Adoration of the Three Magi
in which the founder of the castle, Charles IV, is portrayed.

The
atmosphere of the whole environment was enhanced by the effects
of light which during the day penetrated the coloured stones in the
glazing of the window and the lights of candles and lamps which were
reflected in the polished surfaces of the precious stones on the walls,
in the crystal lenses on the ceiling and in the gilded stucco decoration
of the interior as a whole. lt is not surprising that the magnificence
of the chapel impressed everyone who had the opportunity to visit it.
A chronicler of Charles's time, Benes Krabice of Weitmile, wrote in
one his records that there was no chapel of equal splendour in the whole
world. It was just here that the imperial coronation jewels were placed
along with holy relics and others acquired by Charles IV. Karlstejn
thus became an important centre of the medieval Roman Empire.