His masterpiece is the Chapel of the Holy Cross at Charles' newly completed Karlštejn Castle, near Prague, containing a large series of slightly over-lifesize half-length panel portraits of saints and other notable figures on a gold ground.

Pujmanová[6] states that in about 1309 a sculptor described as 'Magister Theodoricus de Alemania', who could have been an ancestor of his and his brother - the painter Giletto, were active at the court of Charles II of Anjou in Naples.

[7][a] The waiting period for civic rights in Prague was three years, and the newly arrived person wasn't able to become a member of the fraternity of painters straightaway.

The date he was entered in the list of the Prague painters' fraternity (Brotherhood of Saint Luke, established 1346), where he was described as a superior ("primus magister") and as "malerius imperatoris",[8] is uncertain.

In a special document of 28 April 1367, Charles IV certified that Theodoric's court and fields in the village of Mořina would be freed of all taxes and other charges.

The National Gallery in Prague said that they "only few equals in the world: we believe that it is no exaggeration to say that they bear comparison with such artistic monuments and phenomena as the Arena in Padua, the churches at Assisi or Sta, Croce in Florence and the palace of the popes in Avignon.

Theodoric followed on from the work of his predecessor in the service of Charles IV, the Master of the Luxembourg Genealogy,[15] who painted the decoration of the imperial castle-palace at Karlštejn and the 'relic scenes' in the Chapel of the Virgin Mary between 1356 and 1357.

The drawn designs of the compositions, details of the faces and drapery, as well as the overall completion of the most important portraits in the Chapel of the Holy Cross were ascribed to Theodoric.

[22][23] However, some of the faces of saints captivate the viewer's attention with their prominent, seemingly individualized features and psychologized expressions, which anticipate portrait painting of 15th century.

[24] Specialised craftsmen took care of a series of secondary tasks such as preparing the picture panels, the plastic decoration and goldsmith's elements.

[25] There are no records of the painters employed at Theodoric's workshop, however there must have been several of them judging by the scale of the commission and the short time frame of execution,[26] as well as by the ascertained types of underdrawings, confirmed by infrared reflectography.

[5] They can be found in the perfectly executed preparatory drawings on the altar wall that is then repeated in a simpler form or in mirror reverse in the underdrawings of the paintings.

[28] Theodoric's predecessor, the Master of the Luxembourg Genealogy, in all likelihood created the drawn designs on the wall of the Chapel of the Holy Cross.

Clearly made by another talented artist, these paintings stand out with their unusual degree of realism, the spatial design of their still lifes and their sophisticated colour scheme.

The preparation of the panels (beechwood),[33] including a double-layered siliceous and chalk base, is identical to practice in France and Germany but doesn't appear in Italy.

[35][21] In the flesh tones, the moist oil base allows the modelling of smooth transitions into a single layer by adding pigment alla prima (Charlemagne).

[38] Mural paintings in the Chapel of the Holy Cross feature the apocalyptic prophesy - anticipation of the Second coming of Christ on Judgement Day.

The faces are closely related to several of Theodoric's panel paintings and repeatedly feature the characteristic motif of hair and whiskers coiled into individual strands.

With the high quality of its execution, the scene of the Annunciation has much in common with the most advanced techniques used in panels paintings by Theodoric's workshop (St Ambrose).

The rich composition with its landscape scenery in the background is badly damaged, however numerous similar formal analogies rank it alongside Master Theodoric's mural paintings in the Chapel of the Holy Cross.