In this dissertation paintings of Vincent and John from Kastav and their coworkers is shown as a unique entirety that is further analyzed on an iconographic and morphological level. Most of the work deals with the problem of the genesis of painters from Kastav and tries to find out on what tradition have the Kastav painters developed their work. First part of the dissertation is criticly showing all the scientific knowledge about painting workshops from Kastav. France Stelè is the most responsable for all core thesis about development of Gothic painting in Istria by putting Vincent from Kastav into art history after he interpreted the inscription in the church of the Virgin Mary at the Škrilinah near Beram. He assumed impact of the Suha-Bodešče-Prilesje group, Master Bolfgang and Master of the Pazin sanctuary on Vincent's and John's work. Then Branko Fučić makes similar thesis on the foundation of Stele's work. By interpreting name of John from Kastav on the inscription in the church of Holy Trinity in Hrastovlje he contributes to knowledge of Kastav's workshops. Remarkable place in late Gothic wall painting in Istria belongs to so-called Colorful master around whom Branko Fučić constellates whole group of Istrian painters. Branko Fučić also separated individual painting personalities within Kastav's workshop, as well as determined graphic sheet prints that were used as templates and thus he contributed to the understanding of this topics. Fučić's work is followed up by Janez Hofler who systematized all sheet prints and connected Kastav school of painting with early Netherland's painting. All three mentioned art historians mostly contributed knowledge of late Gothic Kastav's workshops. The phenomenon of Kastav's workshops can be observed through historical events caused by politics of the Emperor Friedrich III. in Istria and Karst in second half of 15. century when these regions are administratively more connected with Carniola. In that case relevant is the possible impact of Karst's noble family Raunacher whose representative Jacob was triple associated with Vincent from Kastav which opens the question about commissioner of the wall paintings. Chapter that tells about simultaneous and it's previous workshops reassess the sources of style of the Kastav painters in all regions of comparative coverage. In this chapter is also processed the production of wider Central European region, from Carniola and Carinthia to Bohemia and Rhineland till early Netherland. The painting appearances that had influenced on Kastav's workshops were underlined as well as other phenomenons such as Master Bolfgang and Master of the Pazin sanctuary. Impact of these two last mentioned was reviewed as well as Suha-Bodešče-Prilesje group on Vincent and John from Kastav. South Tyrol painter Leinhart Scherhauf (before known as Leonard from Brixen) is represented and the influence of South Tyrol painting on late Gothic Istrian wall painting is reduced. Kastav workshops are observed similarly to Carinthian oriented workshops that in half of the 15. century overflow Slovenian countries. Bohemian painting has some similarities with Kastav's workshops, such as typology of characters, lyrical expressive lines and using morphology and themes od Soft style. First time in this dissertation Kastav painters are compared with recent art phenomenons in German countries, Bavarian and Rhineland, as source of Knitterstil. It also tells about prominent figures that transmit ideas of the recent early Netherlandish art, such as Martin Schongauer, Friedrich Herlin and Nurnberg school of painting. Ars nova, painting of Flamish primitives influenced the painting of the whole Europe. There are many influence of painting of Robert Campin and Rogier van der Weyden in Kastav's workshop works, but the most significant effect is the early Netherland's graphic arts, Biblia pauperum and Master with the Banderolles, while Israhel van Meckenem can be called German, as well as early Netherland artist. Further chapters of dissertation analyze what Kastav's workshops have in common. In first chapter all definitely identified graphically sources that were used as templates are systematized. Some of the current suggestions were criticized, among them use of sheet prints from Master E. S. Except for so far known sheet prints from Master with the Banderolles and Biblia pauperum, there has been presented new ideas like using sheet prints from Israhel van Meckenem. Some other engravers were mentioned as relevant, such as Master of the Martyrdom of the Ten Thousand and other woodcut editions like Speculum humanae salvationis and Schatzbehalter. The most extensive part of dissertation, that is iconographic analysis of themes that were used in Kastav school of painting, determines prototypes and literary sources, topological system in certan churches and group of themes typical for Kastav school of painting. There are many sources for this subjects, from Central European and early Netherland's painting Ars nova, to Rhineland and Bavarian painting workshops till easter alpine themes. There is also an influence od International Gothic and Soft style, whilest Italian influence is mostly unrecognized. In chapter about morphological analysis ornamental repertoire is represented along with it's borders and brocade patterns and through that repertoire have been determined relations towards artist beyond Kastav painters such as Master from Prilesje, Master Bolfgang, Master from Srednja vas near Šenčurje and Master from Popetre. Further mophological classification separated parts from each individual master. This dissertation is establishing four painters through their work as leaders of their workshops: Master od the Beram Dance of the death, Master od the Beram Adoration of the Magi, Master of the Lovran Martyrdom of Saint George and Master John from Kastav. Less capable are so-called Master of the Hrastovlje Passion and Master of the Beram Passion. In Vincent's workshop, besides till now known wall paintings in church Saint Mary at Škrilinah near Beram and Saint George in Lovran, also are added parts of wall paintings in church Saint Mary below Oprtalj and in cloister of the former Augustinian Monastery of Saint Jerome in Rijeka. Ivan's workshop, on the other hand, besides well known wall paintings in Hrastovlje, Gradišče and Podpeč are added cycles of wall paintings in Barban and Božje Polje. By observing higher quality of painting of Kastav workshops, evaluation of entire corpus of that workshop has changed. Unlike Branko Fučić who gave importance to the Colorful master, this dissertation reveales John from Kastav as much more important figure. In fact, Colorful master is divided into two separated masters of which is one, more skilful, who made scenes of martyrdom of Saint George in Lovran, and the other one, more rustic, who made wall paintings in Dvigrad and Oprtalj.