The castle forms the dominant of Loket and played an important function in its history. We estimate the castle was constructed in the third quarter of the 12th century on basis discovered Romanesque components. Rotunda discovering there in 1966 is from that epoch just as the Tower, foundations of the castle and those of the Northern Palace. Castle has been rebuilt many times, but construction was notably affected with a lack of space on the elevated area thus some component building had to be knocked down or they became parts of the next reconstructions. It is supposed there was also the so-called Rock Room that was linked with the Tower. It enabled relocation to the Tower in danger because the only entrance to the Tower was several metres above surface. In the second half of the 14th century, during the reign of the Luxemburg dynasty, was added the Margrave’s House and after 1412 the County House, and the core of the Northern Palace. The royal family visited the castle very often. Queen Elizabeth of the Přemyslid dynasty used to take refuge at Loket when there was unrest in Bohemia and at the time of conflicts between her and the king John of Luxemburg. The last quarrel happened in 1319 king deprived Elizabeth of her influence on their children and sent her to Mělník. Children were kept there in prison; one of them was future Emperor Charles VI who saw his mother there for the last time. Adult Charles IV stayed in the castle several times. He renewed some town’s privileges and so helped to renewal town after fire. His son Wenceslas IV spent there three-month honeymoon with his second wife Sofia; beautiful Bavarian princess. Next Luxemburg – Emperor Sigismund, when he needed money, mortgaged the castle and its domain, at first to Půta from Illburg and then to Caspar Šlik in 1434.
The Šliks had this possession 110 years. During those years there were next reconstructions. The prominent influence brought Renaissance but mainly desire having comfortable and prestige seat. The construction of the Northern Palace was completed so as a chapel in the eastern wings and a Bastion with adjacent wings. Eastern bastion was converted into family’s archive. In the eastern wing was built a large hall on the first floor. This property was confiscated for the Šlik’s participation in resistance against Ferdinand of Habsburg. The castle was retuned to the town in 1602. At this time there were not any cardinal adaptations. Nevertheless many changes have been since the beginning of the 19th century; the castle was rebuilt into a prison that was used till 1948. The Rock Room was demolished, the third floor of the Palace was pulled down and next other buildings were damaged. The prison was situated in the Big Bastion, eastern wing and in the Northern Palace. There were two floors under ground, one floor on the ground level and two ones above ground. The entry was changed too.
The Museum was located in the Margrave’s House in 1907. The exhibition of fine porcelain has been very famous.
In 1972 – 1993 there was fighting with wood-decaying dry rot and a great reconstruction. The castle has been accessible to the public the year round since 1993.